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What is the cost of painting a hall whose area is 729 sq metres if the rate of painting per square metre is Rs. 28?
Rate of painting per square metre is Rs 28
So painting a hall whose area is 729 sq metres = 28 x 729 = Rs 20412
The average weight of 45 students in a class was calculated as 36 kg. It was later found that the weight of two students in the class was wrongly calculated. The actual weight of one of the boys in the class was 32 kg., but it was calculated as 34 kg. and the weight of another boy in the class was 45 kg., whereas it was calculated as 40 kg. What is the actual average weight of the 45 students in the class?(Rounded off to twodigits after decimal)
Actual weight of all the students
= 36 x 45  34 + 32  40 + 45
= 1620 + 3 = 1623 kg
∴ Actual average weight
= 1623/45 = 36.07 kg
A boat goes 20 km downstream in one hour and the same distance upstream in two hours. The speed of the boat in still water is
Let the speed of boat in still water be x km/hr and the rate of stream be y km/hr
Downstream rate = (x + y) km/hr and upstream rate = (x – y) km/hr
Now, 20 /x + y = 1
⇒ x + y = 20 .....(1)
and 20/x  y = 2
⇒ x  y = 10 .....(2)
From (1) and (2) we have x = 15 km/hr
The difference between the simple interest and the Compound Interest at the rate of 12% p.a on Rs 5,000 for 2 yrs will be
SI = (5000 x 12/100 x 2) = Rs 1200
CI = 5000 x (1 + 12/100 )^{2}  5000
= [5000 x ( 112/100 x 112/100 )]  5000
= 6272  5000 = 1272
CI  SI = 1272  1200 = Rs 72
∠BOC = 7x^{o} + 20^{o} ; ∠COA = 3x^{o} and AB is a straight line. Find (∠BOC  ∠COA) .
∠BOC = 7x^{o} + 20^{o}
∠COA = 3x^{o}
we know that
∠BOC + ∠COA = 180^{o} (Linear pair)
7x^{o} + 20^{o} + 3x^{o} = 180^{o}
⇒ 10x^{o} + 20^{o} = 180^{o}
⇒ 10x^{o} = 180^{o}  20^{o} = 160^{o}
⇒ x^{o} = 160^{o} /10^{o} = 16^{o}
∠BOC = (7 x 16) + 20 = 112 + 20 = 132^{o}
∠COA = 3 x 16 = 48^{o}
∠BOC  ∠COA = 132^{o}  48^{o} = 84^{o}
In fig. (A), 12 x 14/2 = 84.
In fig. (B), 9 x 18/2 = 81.
Let the missing number in fig. (C) be x.
Then, 11 x x/2 = 88 o r x = 88 x 2/11 = 16.
If + means ,  means ×, × means ÷ and ÷ means +, then
36×2+8÷8=?
Mohinder and Surinder entered into a partnership by investing Rs 12000 and Rs 9000 respectively. After 3 months Sudhir joined them with an investment of Rs 15000. What is the share of Sudhir in a halfyearly profit of Rs 9500?
Mohinder : Surinder : Sudhir
= 12,000 x 6 : 9000 x 6 : 15,000 x 3
= 8 : 6 : 5
∴ Sudhir's share
= Rs. (9500 x 5/19 ) = Rs 2500
If the annual rate of simple interest increases from 10% to 12.5%, a man\'s yearly income increases by Rs. 1250. His principal (in Rs.) is :
Let the principal be Rs x Then,
Excluding stoppages, the speed of a bus is 54 kmph and including stoppages, it is 45 kmph. For how many minutes does the bus stop per hour?
Due to stoppages, it covers 9 km less
Time taken to cover 9 km = ( 9/54 x 60) min = 10 min
The greatest value of 3 cos θ + 4 sin θ is
Each of the following questions consists of two sets of figures. Figures 1,2,3 and 4 constitute the Problem Set while figures A,B,C,D and E constitute the Answer Set. There is a definite relationship between figures 1 and 2. Establish a similar relationship between figures 3 and 4 by selecting a suitable figure from the Answer Set .
In the following problem, out of the five figures marked 1, 2, 3, 4 and 5, four are similar in a certain manner. However, one figure is not like the other four. Choose the figure which is different from the rest.
Figure 1 and fig. 3 can be rotated into each other and fig. 4 and fig. 5 can be rotated into each other.
In the following questions, select a figure from amongst the four alternatives, which when placed in the blank space of fig. (X) would complete the pattern.
P, Q, R, S, T, V, W and Z are sitting around a circle facing the center. T is third to the left of Z who is third to the left of P. S is third to the right of P and fourth to the left of Q. R is second to the right of V.
Q. What is R's position with respect to T?
Study the following diagram.
Q. What does number 4 represent?
2^{2} : 3^{3} : : 3^{2} : ?
So the answer should be 4^{3} = 64
A school has four sections A, B, C, D of Class IX students. The results of halfyearly and annual examinations are shown in the table given below. Answer the question based on this table.
Q. How many students are there in Class IX in the school ?
Since the classification of the students on the basis of their results and sections form independent groups, so the total number of students in the class:
= (28 + 23 + 17 + 27 + 14 + 12 + 8 + 13 + 6 + 17 + 9 + 15 + 64 + 55 + 46 + 76) = 430.
A school has four sections A, B, C, D of Class IX students. The results of halfyearly and annual examinations are shown in the table given below. Answer the question based on this table.
Q. Which section has the minimum failure rate in halfyearly examination ?
Total number of failures in halfyearly exams in a section
= [ (Number of students failed in both exams) + (Number of students failed in halfyearly but passed in Annual exams)] in that section
∴ Failure rate in halfyearly exams in Section A
Similarly, failure rate in halfyearly exams in
The failure rate is minimum for Section D
A school has four sections A, B, C, D of Class IX students. The results of halfyearly and annual examinations are shown in the table given below. Answer the question based on this table.
Q. Which section has the maximum pass percentage in annual examination ?
Total number of students passed in annual exams in a section
= [ (No. of students failed in halfyearly but passed in annual exams) + (No. of students passed in both exams)] in that section
∴ Success rate in annual exams in Section A
Similarly, success rate in annual exams in:
The success rate in annual examination is maximum for Section A.
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