Class 7 Exam > Class 7 Notes > Mathematics (Maths) Class 7 > RS Aggarwal Solutions: Simple Interest
RS Aggarwal Solutions: Simple Interest | Mathematics (Maths) Class 7 PDF Download
| Download, print and study this document offline |
Please wait while the PDF view is loading
Page 1
Q u e s t i o n : 1
Find the simple interest and the amount when:
Principal = Rs 6400, rate = 6% p.a. and time = 2 years
S o l u t i o n :
P = Rs. 6400, R = 6%, T = 2 years
S. I. =
P×R×T
100
=
6400×6×2
100
= Rs. 768
Amount=P+S.I.
=6400+768 = Rs. 7168
Q u e s t i o n : 2
Find the simple interest and the amount when:
Principal = Rs 2650, rate = 8% p.a. and time = 2
1
2
years
S o l u t i o n :
P = Rs. 2650, R = 8%, T=2
1
2
years =
5
2
years
S.I. =
P×R×T
100
=
2650×8×5
100×2
= Rs. 530
Amount = P +S. I.
=2650+530 = Rs. 3180
Q u e s t i o n : 3
Find the simple interest and the amount when:
Principal = Rs 1500, rate = 12% p.a. and time = 3 years 3 months.
S o l u t i o n :
P = Rs. 1500, R = 12%, T = 3 +
3
12
=
13
4
years
S.I. =
P×R×T
100
=
1500×12×13
100×4
= Rs. 585
Amount=P+S.I.
=1500+585 =Rs . 2085
Q u e s t i o n : 4
Find the simple interest and the amount when:
Principal = Rs 9600, rate = 7
1
2
%
p.a. and time = 5 months.
S o l u t i o n :
P = Rs. 9600R = 7
1
2
% T = 5 months =
5
12
yearsS. I. =
P×R×T
100
=
9600×15×5
100×2×12
= Rs. 300Amount = P + S. I. = 9600 +300 = Rs. 9900
Q u e s t i o n : 5
Find the simple interest and the amount when:
Principal = Rs 5000, rate = 9% p.a. and time = 146 days.
S o l u t i o n :
P = Rs. 5000 , R = 9% , T = 146 days =
146
365
years
S .I . =
P×R×T
100
=
5000×9×146
100×365
=Rs. 180
Amount=P+S .I .
=5000+180 =Rs . 5180
Q u e s t i o n : 6
Find the time when:
Principal = Rs 6400, SI = Rs 1152 and rate = 6% p.a.
S o l u t i o n :
P = Rs. 6400, S. I. = Rs. 1152, R = 6%
T =
S.I.×100
P×R
=
1152×100
6400×6
=
1152
384
= 3 years
Q u e s t i o n : 7
Find the time when:
Principal = Rs 9540, SI = Rs 1908 and rate = 8% p.a.
S o l u t i o n :
P = Rs. 9540 , S. I. = Rs. 1908, R = 8%
T =
S.I.×100
P×R
=
1908×100
9540×8
=
10
4
=2
1
2
years
Page 2
Q u e s t i o n : 1
Find the simple interest and the amount when:
Principal = Rs 6400, rate = 6% p.a. and time = 2 years
S o l u t i o n :
P = Rs. 6400, R = 6%, T = 2 years
S. I. =
P×R×T
100
=
6400×6×2
100
= Rs. 768
Amount=P+S.I.
=6400+768 = Rs. 7168
Q u e s t i o n : 2
Find the simple interest and the amount when:
Principal = Rs 2650, rate = 8% p.a. and time = 2
1
2
years
S o l u t i o n :
P = Rs. 2650, R = 8%, T=2
1
2
years =
5
2
years
S.I. =
P×R×T
100
=
2650×8×5
100×2
= Rs. 530
Amount = P +S. I.
=2650+530 = Rs. 3180
Q u e s t i o n : 3
Find the simple interest and the amount when:
Principal = Rs 1500, rate = 12% p.a. and time = 3 years 3 months.
S o l u t i o n :
P = Rs. 1500, R = 12%, T = 3 +
3
12
=
13
4
years
S.I. =
P×R×T
100
=
1500×12×13
100×4
= Rs. 585
Amount=P+S.I.
=1500+585 =Rs . 2085
Q u e s t i o n : 4
Find the simple interest and the amount when:
Principal = Rs 9600, rate = 7
1
2
%
p.a. and time = 5 months.
S o l u t i o n :
P = Rs. 9600R = 7
1
2
% T = 5 months =
5
12
yearsS. I. =
P×R×T
100
=
9600×15×5
100×2×12
= Rs. 300Amount = P + S. I. = 9600 +300 = Rs. 9900
Q u e s t i o n : 5
Find the simple interest and the amount when:
Principal = Rs 5000, rate = 9% p.a. and time = 146 days.
S o l u t i o n :
P = Rs. 5000 , R = 9% , T = 146 days =
146
365
years
S .I . =
P×R×T
100
=
5000×9×146
100×365
=Rs. 180
Amount=P+S .I .
=5000+180 =Rs . 5180
Q u e s t i o n : 6
Find the time when:
Principal = Rs 6400, SI = Rs 1152 and rate = 6% p.a.
S o l u t i o n :
P = Rs. 6400, S. I. = Rs. 1152, R = 6%
T =
S.I.×100
P×R
=
1152×100
6400×6
=
1152
384
= 3 years
Q u e s t i o n : 7
Find the time when:
Principal = Rs 9540, SI = Rs 1908 and rate = 8% p.a.
S o l u t i o n :
P = Rs. 9540 , S. I. = Rs. 1908, R = 8%
T =
S.I.×100
P×R
=
1908×100
9540×8
=
10
4
=2
1
2
years
Q u e s t i o n : 8
Find the time when:
Principal = Rs 5000, amount = Rs 6450 and rate = 12% p.a.
S o l u t i o n :
P = Rs. 5000, A=Rs. 6450, R = 12%
S. I. = A -P
= 6450 -5000
= Rs. 1450
T =
S.I×100
P×R
=
1450×100
5000×12
=
29
12
= 2
5
12
=2 years 5 months
Q u e s t i o n : 9
Find the rate when:
Principal = Rs 8250, SI = Rs 1100 and time = 2 years.
S o l u t i o n :
P = Rs. 8250, S. I. = Rs. 1100, T = 2 years
R=
S.I.×100
P×T
=
1100×100
8250×2
=
1100
165
=6.67%
Q u e s t i o n : 1 0
Find the rate when:
Principal = Rs 5200, SI = Rs 975 and time = 2
1
2
years.
S o l u t i o n :
P= Rs. 5200 , S.I.=Rs. 975 [ T=2
1
2
years=
5
2
years]
R=
S.I.×100
P×T
=
975×100×2
5200×5
=
195
26
=7.5%
Q u e s t i o n : 1 1
Find the rate when:
Principal = Rs 3560, amount = Rs 4521.20 and time = 3 years.
S o l u t i o n :
P = Rs. 3560 , A = Rs. 4521. 20 , T = 3 years
S. I. = A -P = 4521. 20 -3560
= Rs. 961. 20
R =
S.I.×100
P×T
=
961.20×100
3560×3
=
96120×100
100×3560×3
=9%
Q u e s t i o n : 1 2
Shanta borrowed Rs 6000 from the State Bank of India for 3 years 8 months at 12% per annum. What amount will clear off her debt?
S o l u t i o n :
P = Rs 6000, R = 12%, T=3 years 8 months = 3
8
12
=
44
12
years
S.I. =
P×R×T
100
=
6000×12×44
100×12
= Rs 2640
A = P +S. I.
= 6000 +2640
= Rs 8640
Q u e s t i o n : 1 3
Hari borrowed Rs 12600 from a moneylender at 15% per annum simple interest. After 3 years, he paid Rs 7070 and gave a goat to clear off the debt. What is the cost of the goat?
S o l u t i o n :
P = Rs. 12600 R = 15% T = 3 years
S.I.=
P×R×T
100
=
12600×15×3
100
=Rs. 5670
A = Rs. 12600 +Rs. 5670 = Rs. 18270
Hari had to pay Rs. 18270 to the money lender, but he paid Rs. 7070 and a goat.
? Cost of the goat = Rs. 18270 -Rs. 7070
= Rs. 11200
Q u e s t i o n : 1 4
The simple interest on a certain sum for 3 years at 10% per annum is Rs 829.50. Find the sum.
S o l u t i o n :
Page 3
Q u e s t i o n : 1
Find the simple interest and the amount when:
Principal = Rs 6400, rate = 6% p.a. and time = 2 years
S o l u t i o n :
P = Rs. 6400, R = 6%, T = 2 years
S. I. =
P×R×T
100
=
6400×6×2
100
= Rs. 768
Amount=P+S.I.
=6400+768 = Rs. 7168
Q u e s t i o n : 2
Find the simple interest and the amount when:
Principal = Rs 2650, rate = 8% p.a. and time = 2
1
2
years
S o l u t i o n :
P = Rs. 2650, R = 8%, T=2
1
2
years =
5
2
years
S.I. =
P×R×T
100
=
2650×8×5
100×2
= Rs. 530
Amount = P +S. I.
=2650+530 = Rs. 3180
Q u e s t i o n : 3
Find the simple interest and the amount when:
Principal = Rs 1500, rate = 12% p.a. and time = 3 years 3 months.
S o l u t i o n :
P = Rs. 1500, R = 12%, T = 3 +
3
12
=
13
4
years
S.I. =
P×R×T
100
=
1500×12×13
100×4
= Rs. 585
Amount=P+S.I.
=1500+585 =Rs . 2085
Q u e s t i o n : 4
Find the simple interest and the amount when:
Principal = Rs 9600, rate = 7
1
2
%
p.a. and time = 5 months.
S o l u t i o n :
P = Rs. 9600R = 7
1
2
% T = 5 months =
5
12
yearsS. I. =
P×R×T
100
=
9600×15×5
100×2×12
= Rs. 300Amount = P + S. I. = 9600 +300 = Rs. 9900
Q u e s t i o n : 5
Find the simple interest and the amount when:
Principal = Rs 5000, rate = 9% p.a. and time = 146 days.
S o l u t i o n :
P = Rs. 5000 , R = 9% , T = 146 days =
146
365
years
S .I . =
P×R×T
100
=
5000×9×146
100×365
=Rs. 180
Amount=P+S .I .
=5000+180 =Rs . 5180
Q u e s t i o n : 6
Find the time when:
Principal = Rs 6400, SI = Rs 1152 and rate = 6% p.a.
S o l u t i o n :
P = Rs. 6400, S. I. = Rs. 1152, R = 6%
T =
S.I.×100
P×R
=
1152×100
6400×6
=
1152
384
= 3 years
Q u e s t i o n : 7
Find the time when:
Principal = Rs 9540, SI = Rs 1908 and rate = 8% p.a.
S o l u t i o n :
P = Rs. 9540 , S. I. = Rs. 1908, R = 8%
T =
S.I.×100
P×R
=
1908×100
9540×8
=
10
4
=2
1
2
years
Q u e s t i o n : 8
Find the time when:
Principal = Rs 5000, amount = Rs 6450 and rate = 12% p.a.
S o l u t i o n :
P = Rs. 5000, A=Rs. 6450, R = 12%
S. I. = A -P
= 6450 -5000
= Rs. 1450
T =
S.I×100
P×R
=
1450×100
5000×12
=
29
12
= 2
5
12
=2 years 5 months
Q u e s t i o n : 9
Find the rate when:
Principal = Rs 8250, SI = Rs 1100 and time = 2 years.
S o l u t i o n :
P = Rs. 8250, S. I. = Rs. 1100, T = 2 years
R=
S.I.×100
P×T
=
1100×100
8250×2
=
1100
165
=6.67%
Q u e s t i o n : 1 0
Find the rate when:
Principal = Rs 5200, SI = Rs 975 and time = 2
1
2
years.
S o l u t i o n :
P= Rs. 5200 , S.I.=Rs. 975 [ T=2
1
2
years=
5
2
years]
R=
S.I.×100
P×T
=
975×100×2
5200×5
=
195
26
=7.5%
Q u e s t i o n : 1 1
Find the rate when:
Principal = Rs 3560, amount = Rs 4521.20 and time = 3 years.
S o l u t i o n :
P = Rs. 3560 , A = Rs. 4521. 20 , T = 3 years
S. I. = A -P = 4521. 20 -3560
= Rs. 961. 20
R =
S.I.×100
P×T
=
961.20×100
3560×3
=
96120×100
100×3560×3
=9%
Q u e s t i o n : 1 2
Shanta borrowed Rs 6000 from the State Bank of India for 3 years 8 months at 12% per annum. What amount will clear off her debt?
S o l u t i o n :
P = Rs 6000, R = 12%, T=3 years 8 months = 3
8
12
=
44
12
years
S.I. =
P×R×T
100
=
6000×12×44
100×12
= Rs 2640
A = P +S. I.
= 6000 +2640
= Rs 8640
Q u e s t i o n : 1 3
Hari borrowed Rs 12600 from a moneylender at 15% per annum simple interest. After 3 years, he paid Rs 7070 and gave a goat to clear off the debt. What is the cost of the goat?
S o l u t i o n :
P = Rs. 12600 R = 15% T = 3 years
S.I.=
P×R×T
100
=
12600×15×3
100
=Rs. 5670
A = Rs. 12600 +Rs. 5670 = Rs. 18270
Hari had to pay Rs. 18270 to the money lender, but he paid Rs. 7070 and a goat.
? Cost of the goat = Rs. 18270 -Rs. 7070
= Rs. 11200
Q u e s t i o n : 1 4
The simple interest on a certain sum for 3 years at 10% per annum is Rs 829.50. Find the sum.
S o l u t i o n :
Let the sum be Rs. P.
S.I. = Rs. 829. 50, T = 3 years, R = 10%
Now, P=
S.I×100
R×T
=
829.50×100
10×3
=
8295
3
= 2765Hence, the sum is Rs. 2765.
Q u e s t i o n : 1 5
A sum when reckoned at 7
1
2
%
per annum amounts to Rs 3920 in 3 years. Find the sum
S o l u t i o n :
Let the required sum be Rs. x.
A = Rs. 3920, R = 7
1
2
%, T = 3 years
Now,
Now, S.I.=
P×R×T
100
=
x×15×3
2×100
=
9x
40
A = P +S. I.
= x +
9x
40
=
40x+9x
40
=
49x
40
But the amount is Rs. 3920.
= >
49x
40
= 3920
= > x =
3920×40
49
=
156800
49
= 3200
Hence, the required sum is Rs. 3200.
Q u e s t i o n : 1 6
A sum of money put at 11% per annum amounts to Rs 4491 in 2 years 3 months. What will it amount to in 3 years at the same rate?
S o l u t i o n :
Given: R=11%, T=2 years 3 months = 2+
3
12
=
27
12
years
Let the required sum be Rs. x.
S.I.=
P×R×T
100
=
x×11×27
9
100×12 4
=
99x
400
A = P +S. I.
= x +
99x
400
=
400x+99x
400
=
499x
400
But the amount is Rs. 4491.
= >
499x
400
= 4491
= > x =
4491×400
499
=
1796400
499
= 3600
Hence, the required sum is Rs. 3600.
? S.I.=
P×R×T
100
=
3600×11×3
100
= Rs. 1188
? Amount=P+S.I.=3600+1188
=Rs. 4788
Q u e s t i o n : 1 7
A sum of money invested at 8% per annum amounts to Rs 12122 in 2 years. What will it amount to in 2 years 8 months at 9% per annum?
S o l u t i o n :
Let the required sum be Rs. x.
S.I.=
P×R×T
100
=
x×8×2
100
=
16x
100
A = P +S. I.
= x +
16x
100
=
100x+16x
100
=
116x
100
But the amount is Rs. 12122.
= >
116x
100
= 12122
= > x =
12122×100
116
= 10450
Now, S.I.=
P×R×T
100
=
10450×9
3
×32
8
100×12 4 1 = Rs. 2508
? A=P+S.I.
= Rs. 10450 + Rs. 2508
= Rs. 12958
Q u e s t i o n : 1 8
At what rate per cent per annum will Rs 3600 amount to Rs 4734 in 3
1
2
years?
S o l u t i o n :
P = Rs. 3600 A = Rs. 4734 T= 3
1
2
=
7
2
years
S. I. = A -P
= 4734 -3600
= Rs. 1134
R=
S.I.×100
P×T
=
1134×100×2
3600×7
=9%
Q u e s t i o n : 1 9
If Rs 640 amounts to Rs 768 in 2 years 6 months, what will Rs 850 amount to in 3 years at the same rate per cent per annum?
S o l u t i o n :
Page 4
Q u e s t i o n : 1
Find the simple interest and the amount when:
Principal = Rs 6400, rate = 6% p.a. and time = 2 years
S o l u t i o n :
P = Rs. 6400, R = 6%, T = 2 years
S. I. =
P×R×T
100
=
6400×6×2
100
= Rs. 768
Amount=P+S.I.
=6400+768 = Rs. 7168
Q u e s t i o n : 2
Find the simple interest and the amount when:
Principal = Rs 2650, rate = 8% p.a. and time = 2
1
2
years
S o l u t i o n :
P = Rs. 2650, R = 8%, T=2
1
2
years =
5
2
years
S.I. =
P×R×T
100
=
2650×8×5
100×2
= Rs. 530
Amount = P +S. I.
=2650+530 = Rs. 3180
Q u e s t i o n : 3
Find the simple interest and the amount when:
Principal = Rs 1500, rate = 12% p.a. and time = 3 years 3 months.
S o l u t i o n :
P = Rs. 1500, R = 12%, T = 3 +
3
12
=
13
4
years
S.I. =
P×R×T
100
=
1500×12×13
100×4
= Rs. 585
Amount=P+S.I.
=1500+585 =Rs . 2085
Q u e s t i o n : 4
Find the simple interest and the amount when:
Principal = Rs 9600, rate = 7
1
2
%
p.a. and time = 5 months.
S o l u t i o n :
P = Rs. 9600R = 7
1
2
% T = 5 months =
5
12
yearsS. I. =
P×R×T
100
=
9600×15×5
100×2×12
= Rs. 300Amount = P + S. I. = 9600 +300 = Rs. 9900
Q u e s t i o n : 5
Find the simple interest and the amount when:
Principal = Rs 5000, rate = 9% p.a. and time = 146 days.
S o l u t i o n :
P = Rs. 5000 , R = 9% , T = 146 days =
146
365
years
S .I . =
P×R×T
100
=
5000×9×146
100×365
=Rs. 180
Amount=P+S .I .
=5000+180 =Rs . 5180
Q u e s t i o n : 6
Find the time when:
Principal = Rs 6400, SI = Rs 1152 and rate = 6% p.a.
S o l u t i o n :
P = Rs. 6400, S. I. = Rs. 1152, R = 6%
T =
S.I.×100
P×R
=
1152×100
6400×6
=
1152
384
= 3 years
Q u e s t i o n : 7
Find the time when:
Principal = Rs 9540, SI = Rs 1908 and rate = 8% p.a.
S o l u t i o n :
P = Rs. 9540 , S. I. = Rs. 1908, R = 8%
T =
S.I.×100
P×R
=
1908×100
9540×8
=
10
4
=2
1
2
years
Q u e s t i o n : 8
Find the time when:
Principal = Rs 5000, amount = Rs 6450 and rate = 12% p.a.
S o l u t i o n :
P = Rs. 5000, A=Rs. 6450, R = 12%
S. I. = A -P
= 6450 -5000
= Rs. 1450
T =
S.I×100
P×R
=
1450×100
5000×12
=
29
12
= 2
5
12
=2 years 5 months
Q u e s t i o n : 9
Find the rate when:
Principal = Rs 8250, SI = Rs 1100 and time = 2 years.
S o l u t i o n :
P = Rs. 8250, S. I. = Rs. 1100, T = 2 years
R=
S.I.×100
P×T
=
1100×100
8250×2
=
1100
165
=6.67%
Q u e s t i o n : 1 0
Find the rate when:
Principal = Rs 5200, SI = Rs 975 and time = 2
1
2
years.
S o l u t i o n :
P= Rs. 5200 , S.I.=Rs. 975 [ T=2
1
2
years=
5
2
years]
R=
S.I.×100
P×T
=
975×100×2
5200×5
=
195
26
=7.5%
Q u e s t i o n : 1 1
Find the rate when:
Principal = Rs 3560, amount = Rs 4521.20 and time = 3 years.
S o l u t i o n :
P = Rs. 3560 , A = Rs. 4521. 20 , T = 3 years
S. I. = A -P = 4521. 20 -3560
= Rs. 961. 20
R =
S.I.×100
P×T
=
961.20×100
3560×3
=
96120×100
100×3560×3
=9%
Q u e s t i o n : 1 2
Shanta borrowed Rs 6000 from the State Bank of India for 3 years 8 months at 12% per annum. What amount will clear off her debt?
S o l u t i o n :
P = Rs 6000, R = 12%, T=3 years 8 months = 3
8
12
=
44
12
years
S.I. =
P×R×T
100
=
6000×12×44
100×12
= Rs 2640
A = P +S. I.
= 6000 +2640
= Rs 8640
Q u e s t i o n : 1 3
Hari borrowed Rs 12600 from a moneylender at 15% per annum simple interest. After 3 years, he paid Rs 7070 and gave a goat to clear off the debt. What is the cost of the goat?
S o l u t i o n :
P = Rs. 12600 R = 15% T = 3 years
S.I.=
P×R×T
100
=
12600×15×3
100
=Rs. 5670
A = Rs. 12600 +Rs. 5670 = Rs. 18270
Hari had to pay Rs. 18270 to the money lender, but he paid Rs. 7070 and a goat.
? Cost of the goat = Rs. 18270 -Rs. 7070
= Rs. 11200
Q u e s t i o n : 1 4
The simple interest on a certain sum for 3 years at 10% per annum is Rs 829.50. Find the sum.
S o l u t i o n :
Let the sum be Rs. P.
S.I. = Rs. 829. 50, T = 3 years, R = 10%
Now, P=
S.I×100
R×T
=
829.50×100
10×3
=
8295
3
= 2765Hence, the sum is Rs. 2765.
Q u e s t i o n : 1 5
A sum when reckoned at 7
1
2
%
per annum amounts to Rs 3920 in 3 years. Find the sum
S o l u t i o n :
Let the required sum be Rs. x.
A = Rs. 3920, R = 7
1
2
%, T = 3 years
Now,
Now, S.I.=
P×R×T
100
=
x×15×3
2×100
=
9x
40
A = P +S. I.
= x +
9x
40
=
40x+9x
40
=
49x
40
But the amount is Rs. 3920.
= >
49x
40
= 3920
= > x =
3920×40
49
=
156800
49
= 3200
Hence, the required sum is Rs. 3200.
Q u e s t i o n : 1 6
A sum of money put at 11% per annum amounts to Rs 4491 in 2 years 3 months. What will it amount to in 3 years at the same rate?
S o l u t i o n :
Given: R=11%, T=2 years 3 months = 2+
3
12
=
27
12
years
Let the required sum be Rs. x.
S.I.=
P×R×T
100
=
x×11×27
9
100×12 4
=
99x
400
A = P +S. I.
= x +
99x
400
=
400x+99x
400
=
499x
400
But the amount is Rs. 4491.
= >
499x
400
= 4491
= > x =
4491×400
499
=
1796400
499
= 3600
Hence, the required sum is Rs. 3600.
? S.I.=
P×R×T
100
=
3600×11×3
100
= Rs. 1188
? Amount=P+S.I.=3600+1188
=Rs. 4788
Q u e s t i o n : 1 7
A sum of money invested at 8% per annum amounts to Rs 12122 in 2 years. What will it amount to in 2 years 8 months at 9% per annum?
S o l u t i o n :
Let the required sum be Rs. x.
S.I.=
P×R×T
100
=
x×8×2
100
=
16x
100
A = P +S. I.
= x +
16x
100
=
100x+16x
100
=
116x
100
But the amount is Rs. 12122.
= >
116x
100
= 12122
= > x =
12122×100
116
= 10450
Now, S.I.=
P×R×T
100
=
10450×9
3
×32
8
100×12 4 1 = Rs. 2508
? A=P+S.I.
= Rs. 10450 + Rs. 2508
= Rs. 12958
Q u e s t i o n : 1 8
At what rate per cent per annum will Rs 3600 amount to Rs 4734 in 3
1
2
years?
S o l u t i o n :
P = Rs. 3600 A = Rs. 4734 T= 3
1
2
=
7
2
years
S. I. = A -P
= 4734 -3600
= Rs. 1134
R=
S.I.×100
P×T
=
1134×100×2
3600×7
=9%
Q u e s t i o n : 1 9
If Rs 640 amounts to Rs 768 in 2 years 6 months, what will Rs 850 amount to in 3 years at the same rate per cent per annum?
S o l u t i o n :
P = Rs. 640, A = Rs. 768, T=2 years 6 months =
5
2
years
S. I. = A -P
= 768 -640
= Rs. 128
R=
S.I.×100
P×T
=
128×100×2
640×5
=8%
P = Rs. 850, R = 8%, T = 3 years
? S.I. =
P×R×T
100
=
850×8×3
100
=
2040
10
=Rs. 204
? A = P +S. I.
= 850 +204
= Rs. 1054
Q u e s t i o n : 2 0
In what time will Rs 5600 amount to Rs 6720 at 8% per annum?
S o l u t i o n :
P = Rs. 5600, A = Rs. 6720, R = 8%
S. I. = A -P
= 6720 -5600
= Rs. 1120
T=
S.I.×100
P×R
=
1120×100
5600×8
=
1120
448
=2
1
2
years
Q u e s t i o n : 2 1
A sum of money becomes
8
5
of itself in 5 years at a certain rate of simple interest. Find the rate of interest.
S o l u t i o n :
Let the sum be Rs. x .
Amount=
8x
5
? S.I.=A -P=
8x
5
-x
=
3x
5
Let the rate be R%.
S.I.=
P×R×T
100
= >
3x
5
=
x×R×5
1
100 20
= > 3x ×20 = R ×x ×5
= > R =
3×x×20
4
x×5
= 12
Hence, the rate of interest is 12 %.
Q u e s t i o n : 2 2
A sum of money lent at simple interest amounts to Rs 783 in 2 years and to Rs 837 in 3 years. Find the sum and the rate per cent per annum.
S o l u t i o n :
Amount in 3 years = (Principal + S. I. for 3 years) = Rs. 837
Amount in 2 years = (Principal + S. I. for 2 years) = Rs. 783
On subtracting:
S. I. for 1 year = (837 -783) = Rs. 54
S. I. for 2 years=
54
1
×2 = Rs. 108
? Sum = Amount for 2 years -S. I. for 2 years
= 783 -108
= Rs. 675
P = Rs. 675, S. I. = Rs. 108 and T = 2 years
R =
S.I.×100
P×T
=
108×100
50 2
675 27 ×2 1
= 8%
Q u e s t i o n : 2 3
A sum of money lent at simple interest amount to Rs 4745 in 3 years and to Rs 5475 in 5 years. Find the sum and the rate per cent per annum.
S o l u t i o n :
Amount in 5 years = (Principal + S. I. for 5 years) = Rs. 5475
Amount in 3 years = (Principal + S. I. for 3 years) = Rs. 4745
On subtracting:
S. I. for 2 years = (5475 -4745) = Rs. 730
S. I. for 3 years=
730
2
×3 = Rs. 1095
? Sum = Amount for 3 years -S. I. for 3 years
= 4745 -1095
= Rs. 3650
P=Rs. 3650, S.I.=Rs. 1095, T=3 years
R=
S.I.×100
P×T
=
1095×100
3650×3
= 10%
Q u e s t i o n : 2 4
Divide Rs 3000 into two parts such that the simple interest on the first part for 4 years at 8% per annum is equal to the simple interest on the second part for 2 years at 9% per annum.
S o l u t i o n :
( )
( )
Page 5
Q u e s t i o n : 1
Find the simple interest and the amount when:
Principal = Rs 6400, rate = 6% p.a. and time = 2 years
S o l u t i o n :
P = Rs. 6400, R = 6%, T = 2 years
S. I. =
P×R×T
100
=
6400×6×2
100
= Rs. 768
Amount=P+S.I.
=6400+768 = Rs. 7168
Q u e s t i o n : 2
Find the simple interest and the amount when:
Principal = Rs 2650, rate = 8% p.a. and time = 2
1
2
years
S o l u t i o n :
P = Rs. 2650, R = 8%, T=2
1
2
years =
5
2
years
S.I. =
P×R×T
100
=
2650×8×5
100×2
= Rs. 530
Amount = P +S. I.
=2650+530 = Rs. 3180
Q u e s t i o n : 3
Find the simple interest and the amount when:
Principal = Rs 1500, rate = 12% p.a. and time = 3 years 3 months.
S o l u t i o n :
P = Rs. 1500, R = 12%, T = 3 +
3
12
=
13
4
years
S.I. =
P×R×T
100
=
1500×12×13
100×4
= Rs. 585
Amount=P+S.I.
=1500+585 =Rs . 2085
Q u e s t i o n : 4
Find the simple interest and the amount when:
Principal = Rs 9600, rate = 7
1
2
%
p.a. and time = 5 months.
S o l u t i o n :
P = Rs. 9600R = 7
1
2
% T = 5 months =
5
12
yearsS. I. =
P×R×T
100
=
9600×15×5
100×2×12
= Rs. 300Amount = P + S. I. = 9600 +300 = Rs. 9900
Q u e s t i o n : 5
Find the simple interest and the amount when:
Principal = Rs 5000, rate = 9% p.a. and time = 146 days.
S o l u t i o n :
P = Rs. 5000 , R = 9% , T = 146 days =
146
365
years
S .I . =
P×R×T
100
=
5000×9×146
100×365
=Rs. 180
Amount=P+S .I .
=5000+180 =Rs . 5180
Q u e s t i o n : 6
Find the time when:
Principal = Rs 6400, SI = Rs 1152 and rate = 6% p.a.
S o l u t i o n :
P = Rs. 6400, S. I. = Rs. 1152, R = 6%
T =
S.I.×100
P×R
=
1152×100
6400×6
=
1152
384
= 3 years
Q u e s t i o n : 7
Find the time when:
Principal = Rs 9540, SI = Rs 1908 and rate = 8% p.a.
S o l u t i o n :
P = Rs. 9540 , S. I. = Rs. 1908, R = 8%
T =
S.I.×100
P×R
=
1908×100
9540×8
=
10
4
=2
1
2
years
Q u e s t i o n : 8
Find the time when:
Principal = Rs 5000, amount = Rs 6450 and rate = 12% p.a.
S o l u t i o n :
P = Rs. 5000, A=Rs. 6450, R = 12%
S. I. = A -P
= 6450 -5000
= Rs. 1450
T =
S.I×100
P×R
=
1450×100
5000×12
=
29
12
= 2
5
12
=2 years 5 months
Q u e s t i o n : 9
Find the rate when:
Principal = Rs 8250, SI = Rs 1100 and time = 2 years.
S o l u t i o n :
P = Rs. 8250, S. I. = Rs. 1100, T = 2 years
R=
S.I.×100
P×T
=
1100×100
8250×2
=
1100
165
=6.67%
Q u e s t i o n : 1 0
Find the rate when:
Principal = Rs 5200, SI = Rs 975 and time = 2
1
2
years.
S o l u t i o n :
P= Rs. 5200 , S.I.=Rs. 975 [ T=2
1
2
years=
5
2
years]
R=
S.I.×100
P×T
=
975×100×2
5200×5
=
195
26
=7.5%
Q u e s t i o n : 1 1
Find the rate when:
Principal = Rs 3560, amount = Rs 4521.20 and time = 3 years.
S o l u t i o n :
P = Rs. 3560 , A = Rs. 4521. 20 , T = 3 years
S. I. = A -P = 4521. 20 -3560
= Rs. 961. 20
R =
S.I.×100
P×T
=
961.20×100
3560×3
=
96120×100
100×3560×3
=9%
Q u e s t i o n : 1 2
Shanta borrowed Rs 6000 from the State Bank of India for 3 years 8 months at 12% per annum. What amount will clear off her debt?
S o l u t i o n :
P = Rs 6000, R = 12%, T=3 years 8 months = 3
8
12
=
44
12
years
S.I. =
P×R×T
100
=
6000×12×44
100×12
= Rs 2640
A = P +S. I.
= 6000 +2640
= Rs 8640
Q u e s t i o n : 1 3
Hari borrowed Rs 12600 from a moneylender at 15% per annum simple interest. After 3 years, he paid Rs 7070 and gave a goat to clear off the debt. What is the cost of the goat?
S o l u t i o n :
P = Rs. 12600 R = 15% T = 3 years
S.I.=
P×R×T
100
=
12600×15×3
100
=Rs. 5670
A = Rs. 12600 +Rs. 5670 = Rs. 18270
Hari had to pay Rs. 18270 to the money lender, but he paid Rs. 7070 and a goat.
? Cost of the goat = Rs. 18270 -Rs. 7070
= Rs. 11200
Q u e s t i o n : 1 4
The simple interest on a certain sum for 3 years at 10% per annum is Rs 829.50. Find the sum.
S o l u t i o n :
Let the sum be Rs. P.
S.I. = Rs. 829. 50, T = 3 years, R = 10%
Now, P=
S.I×100
R×T
=
829.50×100
10×3
=
8295
3
= 2765Hence, the sum is Rs. 2765.
Q u e s t i o n : 1 5
A sum when reckoned at 7
1
2
%
per annum amounts to Rs 3920 in 3 years. Find the sum
S o l u t i o n :
Let the required sum be Rs. x.
A = Rs. 3920, R = 7
1
2
%, T = 3 years
Now,
Now, S.I.=
P×R×T
100
=
x×15×3
2×100
=
9x
40
A = P +S. I.
= x +
9x
40
=
40x+9x
40
=
49x
40
But the amount is Rs. 3920.
= >
49x
40
= 3920
= > x =
3920×40
49
=
156800
49
= 3200
Hence, the required sum is Rs. 3200.
Q u e s t i o n : 1 6
A sum of money put at 11% per annum amounts to Rs 4491 in 2 years 3 months. What will it amount to in 3 years at the same rate?
S o l u t i o n :
Given: R=11%, T=2 years 3 months = 2+
3
12
=
27
12
years
Let the required sum be Rs. x.
S.I.=
P×R×T
100
=
x×11×27
9
100×12 4
=
99x
400
A = P +S. I.
= x +
99x
400
=
400x+99x
400
=
499x
400
But the amount is Rs. 4491.
= >
499x
400
= 4491
= > x =
4491×400
499
=
1796400
499
= 3600
Hence, the required sum is Rs. 3600.
? S.I.=
P×R×T
100
=
3600×11×3
100
= Rs. 1188
? Amount=P+S.I.=3600+1188
=Rs. 4788
Q u e s t i o n : 1 7
A sum of money invested at 8% per annum amounts to Rs 12122 in 2 years. What will it amount to in 2 years 8 months at 9% per annum?
S o l u t i o n :
Let the required sum be Rs. x.
S.I.=
P×R×T
100
=
x×8×2
100
=
16x
100
A = P +S. I.
= x +
16x
100
=
100x+16x
100
=
116x
100
But the amount is Rs. 12122.
= >
116x
100
= 12122
= > x =
12122×100
116
= 10450
Now, S.I.=
P×R×T
100
=
10450×9
3
×32
8
100×12 4 1 = Rs. 2508
? A=P+S.I.
= Rs. 10450 + Rs. 2508
= Rs. 12958
Q u e s t i o n : 1 8
At what rate per cent per annum will Rs 3600 amount to Rs 4734 in 3
1
2
years?
S o l u t i o n :
P = Rs. 3600 A = Rs. 4734 T= 3
1
2
=
7
2
years
S. I. = A -P
= 4734 -3600
= Rs. 1134
R=
S.I.×100
P×T
=
1134×100×2
3600×7
=9%
Q u e s t i o n : 1 9
If Rs 640 amounts to Rs 768 in 2 years 6 months, what will Rs 850 amount to in 3 years at the same rate per cent per annum?
S o l u t i o n :
P = Rs. 640, A = Rs. 768, T=2 years 6 months =
5
2
years
S. I. = A -P
= 768 -640
= Rs. 128
R=
S.I.×100
P×T
=
128×100×2
640×5
=8%
P = Rs. 850, R = 8%, T = 3 years
? S.I. =
P×R×T
100
=
850×8×3
100
=
2040
10
=Rs. 204
? A = P +S. I.
= 850 +204
= Rs. 1054
Q u e s t i o n : 2 0
In what time will Rs 5600 amount to Rs 6720 at 8% per annum?
S o l u t i o n :
P = Rs. 5600, A = Rs. 6720, R = 8%
S. I. = A -P
= 6720 -5600
= Rs. 1120
T=
S.I.×100
P×R
=
1120×100
5600×8
=
1120
448
=2
1
2
years
Q u e s t i o n : 2 1
A sum of money becomes
8
5
of itself in 5 years at a certain rate of simple interest. Find the rate of interest.
S o l u t i o n :
Let the sum be Rs. x .
Amount=
8x
5
? S.I.=A -P=
8x
5
-x
=
3x
5
Let the rate be R%.
S.I.=
P×R×T
100
= >
3x
5
=
x×R×5
1
100 20
= > 3x ×20 = R ×x ×5
= > R =
3×x×20
4
x×5
= 12
Hence, the rate of interest is 12 %.
Q u e s t i o n : 2 2
A sum of money lent at simple interest amounts to Rs 783 in 2 years and to Rs 837 in 3 years. Find the sum and the rate per cent per annum.
S o l u t i o n :
Amount in 3 years = (Principal + S. I. for 3 years) = Rs. 837
Amount in 2 years = (Principal + S. I. for 2 years) = Rs. 783
On subtracting:
S. I. for 1 year = (837 -783) = Rs. 54
S. I. for 2 years=
54
1
×2 = Rs. 108
? Sum = Amount for 2 years -S. I. for 2 years
= 783 -108
= Rs. 675
P = Rs. 675, S. I. = Rs. 108 and T = 2 years
R =
S.I.×100
P×T
=
108×100
50 2
675 27 ×2 1
= 8%
Q u e s t i o n : 2 3
A sum of money lent at simple interest amount to Rs 4745 in 3 years and to Rs 5475 in 5 years. Find the sum and the rate per cent per annum.
S o l u t i o n :
Amount in 5 years = (Principal + S. I. for 5 years) = Rs. 5475
Amount in 3 years = (Principal + S. I. for 3 years) = Rs. 4745
On subtracting:
S. I. for 2 years = (5475 -4745) = Rs. 730
S. I. for 3 years=
730
2
×3 = Rs. 1095
? Sum = Amount for 3 years -S. I. for 3 years
= 4745 -1095
= Rs. 3650
P=Rs. 3650, S.I.=Rs. 1095, T=3 years
R=
S.I.×100
P×T
=
1095×100
3650×3
= 10%
Q u e s t i o n : 2 4
Divide Rs 3000 into two parts such that the simple interest on the first part for 4 years at 8% per annum is equal to the simple interest on the second part for 2 years at 9% per annum.
S o l u t i o n :
( )
( )
Let the first part be Rs. x.
Second part = (3000 -x)
? S. I. on x at 8% per annum for 4 years =
x×8×4
2 1
100 50 25 =
8x
25
S. I. on (3000 -x) at 9% per annum =
3000-x ×9×2
1
100 50
=
27000-9x
50
?
8x
25
=
27000-9x
50
= > 8x =
27000-9x ×25
1
50 2
= > 16x = 27000 -9x
= > 16x +9x = 27000
= > x =
27000
1080
25 1
= 1080
? First part = Rs.1080
Second part = (3000 -1080) = Rs. 1920
Q u e s t i o n : 2 5
Divide Rs 3600 into two parts such that if one part be lent at 9% per annum and the other at 10% per annum, the total annum income is Rs 333.
S o l u t i o n :
Let the first part be Rs. x.
Second part = (3600 -x)
? S. I. on x at 9% per annum for 1 years =
x×9×1
100
=
9x
100
And, S. I. on (3600 -x) at 10% per annum =
3600-x ×1×10
1
100
=
3600-x
10
?
9x
100
+
3600-x
10
= 333
= >
9x+36000-10x
100
= 333
= > -x +36000 = 33300
= > -x = 33300 -36000
= > -x = -2700
= > x = 2700
First part = Rs. 2700
Second part = (3600 -2700) = Rs. 900
Q u e s t i o n : 2 6
Mark
? against the correct answer
The simple interest on Rs 6250 at 4% per annum for 6 months is
a
Rs 125
b
Rs 150
c
Rs 175
d
Rs 135
S o l u t i o n :
(a) Rs. 125Principal = Rs. 6250
Simple Interest = 4% per annum
Time = 6 months =
1
2
years
Simple Interest=
P×R×T
100
Simple Interest=
6250×4×1
100×2
Simple Interest=
250
2
= Rs. 125
Q u e s t i o n : 2 7
Mark
? against the correct answer
A sum amounts to Rs 3605 in 219 days at 5% per annum. The sum is
a
Rs 3250
b
Rs 3500
c
Rs 3400
d
Rs 3550
S o l u t i o n :
b
Rs.3500
Amount =Rs. 3605
Time =
219
365
days=
219
365
days
Rate=5% per ? annum
Amount = Sum +
Sum×Rate×Time
100
Amount = Sum (1+
Rate×Time
100
)
Sum=
3605
1+
5
100
×
219
365
=
3605×36500
37595
Sum= Rs. 3500
( )
( )
( )
Read More
|
76 videos|345 docs|39 tests
|
FAQs on RS Aggarwal Solutions: Simple Interest - Mathematics (Maths) Class 7
| 1. What is the formula for calculating simple interest? |  |
Ans. The formula for calculating simple interest is:
Simple Interest = (Principal * Rate * Time) / 100.
| 2. How is simple interest different from compound interest? | |
Ans. Simple interest is calculated only on the principal amount, whereas compound interest is calculated on both the principal amount and the accumulated interest. Compound interest generally yields a higher amount compared to simple interest.
| 3. Can you provide an example of calculating simple interest? | |
Ans. Certainly! Let's say you deposit $500 in a bank account with an annual interest rate of 5%. After 2 years, the simple interest earned can be calculated as follows:
Simple Interest = (500 * 5 * 2) / 100 = $50.
Therefore, the simple interest earned after 2 years would be $50.
| 4. What is the significance of time in calculating simple interest? | |
Ans. Time plays a crucial role in calculating simple interest as it determines the duration for which the principal amount is borrowed or invested. The longer the time period, the higher the interest earned or paid.
| 5. How can simple interest be useful in everyday life? | |
Ans. Simple interest is applicable in various real-life scenarios, such as borrowing or lending money, investing in fixed deposits, or calculating interest on credit card balances. It helps individuals understand the interest they owe or earn on their financial transactions, enabling them to make informed decisions.
Related Exams
About this Document
|
4.82/5 Rating |
|
Nov 21, 2024 Last updated |
Document Description: RS Aggarwal Solutions: Simple Interest for Class 7 2024 is part of Mathematics (Maths) Class 7 preparation.
The notes and questions for RS Aggarwal Solutions: Simple Interest have been prepared according to the Class 7 exam syllabus. Information about RS Aggarwal Solutions: Simple Interest covers topics
like and RS Aggarwal Solutions: Simple Interest Example, for Class 7 2024 Exam. Find important definitions, questions, notes, meanings, examples, exercises and tests below for RS Aggarwal Solutions: Simple Interest.
Introduction of RS Aggarwal Solutions: Simple Interest in English is available as part of our Mathematics (Maths) Class 7
for Class 7 & RS Aggarwal Solutions: Simple Interest in Hindi for Mathematics (Maths) Class 7 course.
Download more important topics related with notes, lectures and mock test series for Class 7
Exam by signing up for free. Class 7: RS Aggarwal Solutions: Simple Interest | Mathematics (Maths) Class 7
Description
Full syllabus notes, lecture & questions for RS Aggarwal Solutions: Simple Interest | Mathematics (Maths) Class 7 - Class 7 | Plus excerises question with solution to help you revise complete syllabus for Mathematics (Maths) Class 7 | Best notes, free PDF download
Information about RS Aggarwal Solutions: Simple Interest
In this doc you can find the meaning of RS Aggarwal Solutions: Simple Interest defined & explained in the simplest way possible. Besides explaining types of
RS Aggarwal Solutions: Simple Interest theory, EduRev gives you an ample number of questions to practice RS Aggarwal Solutions: Simple Interest tests, examples and also practice Class 7
tests
|
Explore Courses for Class 7 exam
|
|
Signup for Free!
Signup to see your scores go up within 7 days! Learn & Practice with 1000+ FREE Notes, Videos & Tests.
Related Searches
RS Aggarwal Solutions: Simple Interest | Mathematics (Maths) Class 7
,mock tests for examination
,practice quizzes
,Previous Year Questions with Solutions
,Important questions
,shortcuts and tricks
,study material
,Objective type Questions
,Viva Questions
,Exam
,Extra Questions
,past year papers
,RS Aggarwal Solutions: Simple Interest | Mathematics (Maths) Class 7
,Sample Paper
,Free
,RS Aggarwal Solutions: Simple Interest | Mathematics (Maths) Class 7
,MCQs
,Semester Notes
,video lectures
,Summary
,ppt
;
Additional Information about RS Aggarwal Solutions: Simple Interest for Class 7 Preparation
RS Aggarwal Solutions: Simple Interest Free PDF Download
The RS Aggarwal Solutions: Simple Interest is an invaluable resource that delves deep into the core of the Class 7 exam.
These study notes are curated by experts and cover all the essential topics and concepts, making your preparation more efficient and effective.
With the help of these notes, you can grasp complex subjects quickly, revise important points easily,
and reinforce your understanding of key concepts. The study notes are presented in a concise and easy-to-understand manner,
allowing you to optimize your learning process. Whether you're looking for best-recommended books, sample papers, study material,
or toppers' notes, this PDF has got you covered. Download the RS Aggarwal Solutions: Simple Interest now and kickstart your journey towards success in the Class 7 exam.
Importance of RS Aggarwal Solutions: Simple Interest
The importance of RS Aggarwal Solutions: Simple Interest cannot be overstated, especially for Class 7 aspirants.
This document holds the key to success in the Class 7 exam.
It offers a detailed understanding of the concept, providing invaluable insights into the topic.
By knowing the concepts well in advance, students can plan their preparation effectively.
Utilize this indispensable guide for a well-rounded preparation and achieve your desired results.
RS Aggarwal Solutions: Simple Interest Notes
RS Aggarwal Solutions: Simple Interest Notes offer in-depth insights into the specific topic to help you master it with ease.
This comprehensive document covers all aspects related to RS Aggarwal Solutions: Simple Interest.
It includes detailed information about the exam syllabus, recommended books, and study materials for a well-rounded preparation.
Practice papers and question papers enable you to assess your progress effectively.
Additionally, the paper analysis provides valuable tips for tackling the exam strategically.
Access to Toppers' notes gives you an edge in understanding complex concepts.
Whether you're a beginner or aiming for advanced proficiency, RS Aggarwal Solutions: Simple Interest Notes on EduRev are your ultimate resource for success.
RS Aggarwal Solutions: Simple Interest Class 7 Questions
The "RS Aggarwal Solutions: Simple Interest Class 7 Questions" guide is a valuable resource for all aspiring students preparing for the
Class 7 exam. It focuses on providing a wide range of practice questions to help students gauge
their understanding of the exam topics. These questions cover the entire syllabus, ensuring comprehensive preparation.
The guide includes previous years' question papers for students to familiarize themselves with the exam's format and difficulty level.
Additionally, it offers subject-specific question banks, allowing students to focus on weak areas and improve their performance.
Study RS Aggarwal Solutions: Simple Interest on the App
Students of Class 7 can study RS Aggarwal Solutions: Simple Interest alongwith tests & analysis from the EduRev app,
which will help them while preparing for their exam. Apart from the RS Aggarwal Solutions: Simple Interest,
students can also utilize the EduRev App for other study materials such as previous year question papers, syllabus, important questions, etc.
The EduRev App will make your learning easier as you can access it from anywhere you want.
The content of RS Aggarwal Solutions: Simple Interest is prepared as per the latest Class 7 syllabus.
|
© EduRev
|
Education Revolution
|
Follow Us
|
Signup to see your scores
go up within 7 days!
Access 1000+ FREE Docs, Videos and Tests
Takes less than 10 seconds to signup