All Exams >
Class 7 >
Advance Learner Course: Mathematics (Maths) Class 7 >
All Questions
All questions of Linear Equations in One Variable for Class 7 Exam
Solve: 3x = 12- a)15
- b)4
- c)9
- d)3
Correct answer is 'B'. Can you explain this answer?
Solve: 3x = 12
a)
15
b)
4
c)
9
d)
3
|
Tanu Kumari answered |
The answer is 4(four) if correct than pls try to following me or upvote me i beg u
Solve: 4y = 20- a)5
- b)16
- c)4
- d)24
Correct answer is option 'A'. Can you explain this answer?
Solve: 4y = 20
a)
5
b)
16
c)
4
d)
24
|
Anu Jain answered |
4y = 20 y = 20/4 y = 5
An algebraic equation is an _________ involving variables.
- a)Number
- b)Equality
- c)Equation
- d)None of these
Correct answer is option 'B'. Can you explain this answer?
An algebraic equation is an _________ involving variables.
a)
Number
b)
Equality
c)
Equation
d)
None of these
|
Aarya Deshpande answered |
An algebraic equation is an equality that involves variables. It states that two expressions are equal to each other, typically connected by an equals sign =. For example, in the equation 2x+3=7, the expression 2x+3 is equal to 7. The equation shows the relationship between the variable x and the constants.
Can you explain the answer of this question below:Solve 2x − 3 = x + 2
- A:
4
- B:
5
- C:
3
- D:
0
The answer is b.
Solve 2x − 3 = x + 2
4
5
3
0
|
Geetika Shah answered |
Given, 2x - 3 = x + 2
Transposing 'x' to L.H.S
⇒ 2x - x - 3 = 2
⇒ x - 3 = 2
Transposing '3' to R.H.S
⇒ x = 2 + 3
⇒ x = 5.
Therefore, option (b) is the correct answer.
Transposing 'x' to L.H.S
⇒ 2x - x - 3 = 2
⇒ x - 3 = 2
Transposing '3' to R.H.S
⇒ x = 2 + 3
⇒ x = 5.
Therefore, option (b) is the correct answer.
Solve 2y + 9 = 4.- a)-5/2
- b)1/2
- c)2
- d)none of these
Correct answer is option 'A'. Can you explain this answer?
Solve 2y + 9 = 4.
a)
-5/2
b)
1/2
c)
2
d)
none of these
|
Amit Sharma answered |
Given, 2y + 9 =4
Transposing '9' to R.H.S, we get
2y = 4-9
⇒ 2y = -5
Therefore, y = -5/2
Hence, option 'A' is correct.
Transposing '9' to R.H.S, we get
2y = 4-9
⇒ 2y = -5
Therefore, y = -5/2
Hence, option 'A' is correct.
Solve: y + 3 = 10- a)13
- b)7
- c)-7
- d)none of these
Correct answer is option 'B'. Can you explain this answer?
Solve: y + 3 = 10
a)
13
b)
7
c)
-7
d)
none of these
|
|
Ananya Das answered |
y + 3 = 10
y = 10 - 3
y = 7
y = 10 - 3
y = 7
An algebraic equation is an _________ involving variables.- a)number
- b)equation
- c)equality
- d)none of these
Correct answer is 'C'. Can you explain this answer?
An algebraic equation is an _________ involving variables.
a)
number
b)
equation
c)
equality
d)
none of these
|
Amrutha Saini answered |
An algebraic equation is an equality involving variables. It has an equality sign. The expression on the left of the equality sign is the Left Hand Side (LHS). The expression on the right of the equality sign is the Right Hand Side (RHS).
Example: 2x - 3 = 7
Here, 2x - 3 = LHS
7 = RHS
Solve: 5x+ 9 = 5 + 3x
- a)-2
- b)-1
- c)2
- d)none of these
Correct answer is option 'A'. Can you explain this answer?
Solve: 5x+ 9 = 5 + 3x
a)
-2
b)
-1
c)
2
d)
none of these
|
Rishika Mukherjee answered |
To solve the given equation, we need to isolate the variable x.
Given equation: 5x + 9 = 5(3x)
Step 1: Distribute the 5 on the right side of the equation:
5x + 9 = 15x
Step 2: Move all the terms containing x to one side of the equation by subtracting 5x from both sides:
9 = 15x - 5x
Simplifying the equation gives:
9 = 10x
Step 3: To solve for x, divide both sides of the equation by 10:
9/10 = x
Simplifying the fraction gives:
x = 0.9
Therefore, the correct answer is option A, -2.
Explanation:
The given equation is 5x + 9 = 5(3x). We can solve this equation step by step to find the value of x. By distributing the 5 on the right side, we get 5x + 9 = 15x. Next, we need to move all the terms containing x to one side of the equation. By subtracting 5x from both sides, we get 9 = 15x - 5x, which simplifies to 9 = 10x. To solve for x, we divide both sides of the equation by 10, giving us 9/10 = x. Simplifying the fraction, we find that x = 0.9. However, this does not match any of the given answer choices. Therefore, the correct answer is none of these (d), not option A (-2).
Given equation: 5x + 9 = 5(3x)
Step 1: Distribute the 5 on the right side of the equation:
5x + 9 = 15x
Step 2: Move all the terms containing x to one side of the equation by subtracting 5x from both sides:
9 = 15x - 5x
Simplifying the equation gives:
9 = 10x
Step 3: To solve for x, divide both sides of the equation by 10:
9/10 = x
Simplifying the fraction gives:
x = 0.9
Therefore, the correct answer is option A, -2.
Explanation:
The given equation is 5x + 9 = 5(3x). We can solve this equation step by step to find the value of x. By distributing the 5 on the right side, we get 5x + 9 = 15x. Next, we need to move all the terms containing x to one side of the equation. By subtracting 5x from both sides, we get 9 = 15x - 5x, which simplifies to 9 = 10x. To solve for x, we divide both sides of the equation by 10, giving us 9/10 = x. Simplifying the fraction, we find that x = 0.9. However, this does not match any of the given answer choices. Therefore, the correct answer is none of these (d), not option A (-2).
Solve: 3x = 12- a)15
- b)4
- c)9
- d)3
Correct answer is option 'B'. Can you explain this answer?
Solve: 3x = 12
a)
15
b)
4
c)
9
d)
3
|
|
Amit Sharma answered |
Given, 3x = 12
Transposing '3' to R.H.S, we get
x = 12/3
⇒ x = 4
Transposing '3' to R.H.S, we get
x = 12/3
⇒ x = 4
or
Divide both sides by '3' to get the value of x
3x/3 = 12/3
⇒ x = 4
Divide both sides by '3' to get the value of x
3x/3 = 12/3
⇒ x = 4
The sum of three consecutive multiples of 7 is 357. Find the smallest multiple.
- a)112
- b)126
- c)119
- d)116
Correct answer is option 'A'. Can you explain this answer?
The sum of three consecutive multiples of 7 is 357. Find the smallest multiple.
a)
112
b)
126
c)
119
d)
116
|
|
Anita Menon answered |
Given,
Sum of multiples of 7 = 357
Let the numbers be x, x + 7 , x + 14
ATP,
x + x + 7 + x + 14 = 357
3x + 21 = 357
3x = 357 - 21
3x = 336
x = 336/3
x = 112
Therefore,
the smallest multiple is x = 112
Sum of multiples of 7 = 357
Let the numbers be x, x + 7 , x + 14
ATP,
x + x + 7 + x + 14 = 357
3x + 21 = 357
3x = 357 - 21
3x = 336
x = 336/3
x = 112
Therefore,
the smallest multiple is x = 112
A store has provision which would last for a certain number of men for 21 days. For one seventh of the men it will last for how many days?- a)147
- b)158
- c)129
- d)174
- e)None of these
Correct answer is option 'A'. Can you explain this answer?
A store has provision which would last for a certain number of men for 21 days. For one seventh of the men it will last for how many days?
a)
147
b)
158
c)
129
d)
174
e)
None of these
|
Nclex Coaching Centre answered |
-
- Let’s assume the original number of men is M.
- The provisions last for 21 days for M men.
- Calculate Total Provisions:
- Total provisions can be represented as:
- Total Provisions = Number of Men × Number of Days
- So, Total Provisions = M × 21
- Total provisions can be represented as:
- Determine the New Scenario:
- Now, only one-seventh of the original number of men will be consuming the provisions.
- New Number of Men = M/7
- Now, only one-seventh of the original number of men will be consuming the provisions.
- Set Up the Equation for the New Scenario:
- Let’s denote the number of days the provisions will last in the new scenario as D.
- Using the proportionality:
- New Number of Men × New Number of Days = Total Provisions
- So, (M/7) × D = M × 21
- Simplify the Equation:
- Divide both sides of the equation by M to eliminate M:
- D/7 = 21
- Divide both sides of the equation by M to eliminate M:
- Solve for D:
- Multiply both sides by 7:
- D = 21 × 7
- D = 147
- Multiply both sides by 7:
What will be the solution of these equations ax+by=a-b, bx-ay=a+b - a) x=1, y=2
- b) x=2,y=-1
- c) x=-2, y=-2
- d) x=1, y=-1
Correct answer is option 'D'. Can you explain this answer?
What will be the solution of these equations ax+by=a-b, bx-ay=a+b
a)
x=1, y=2
b)
x=2,y=-1
c)
x=-2, y=-2
d)
x=1, y=-1
|
Malavika Basu answered |
Ax+by=a-bax=a-b-byx=a-b-by/a←bx-ay=a+bsubstitutingb(a-b-by/a)-ay=a+bab-bx-bxy/a-ay=a+bab-bx-bxy-axy/a=a+bab-
An MNC company employed 25 men to do the official work in 32 days. After 16 days, it employed 5 more men and work was finished one day earlier. If it had not employed additional men, it would have been behind by how many days?
- a)1 day
- b)2 days
- c)3 days
- d)2.5 days
- e)None of these
Correct answer is option 'B'. Can you explain this answer?
An MNC company employed 25 men to do the official work in 32 days. After 16 days, it employed 5 more men and work was finished one day earlier. If it had not employed additional men, it would have been behind by how many days?
a)
1 day
b)
2 days
c)
3 days
d)
2.5 days
e)
None of these
|
|
Amit Kumar answered |
Let 1 person do 1 unit of work in 1 day
When 25 people are employed, amount of work in 1 day = 25 units
Amount of work in 16 days = 25*16 = 400
After 16 days, 5 more people are employed and work is completed in 15 days
So work done in next 15 days = 30*15 = 450
If those 5 people are not employed , No. of days needed to complete 450 units of work = 450/25 = 18
But they were supposed to complete the work by 16 days
Hence 2 extra days are needed by 25 people.
When 25 people are employed, amount of work in 1 day = 25 units
Amount of work in 16 days = 25*16 = 400
After 16 days, 5 more people are employed and work is completed in 15 days
So work done in next 15 days = 30*15 = 450
If those 5 people are not employed , No. of days needed to complete 450 units of work = 450/25 = 18
But they were supposed to complete the work by 16 days
Hence 2 extra days are needed by 25 people.
Solve: x − 2 = 7
- a)-5
- b)5
- c)9
- d)none of these
Correct answer is option 'C'. Can you explain this answer?
Solve: x − 2 = 7
a)
-5
b)
5
c)
9
d)
none of these
|
Jay Saini answered |
I'm sorry, but your equation is incomplete. Please provide the complete equation or inequality so I can help you solve it.
A number is 56 greater than the average of its third, quarter and one-twelfth. Find the number.- a)85
- b)64
- c)72
- d)40
Correct answer is option 'C'. Can you explain this answer?
A number is 56 greater than the average of its third, quarter and one-twelfth. Find the number.
a)
85
b)
64
c)
72
d)
40
|
Maahi Chakraborty answered |
Let the number be x. Then, One-third of x = x/3, Quarter of x = x/4
One-twelfth of x = x/12
Average of third, quarter and one-twelfth of
One-twelfth of x = x/12
Average of third, quarter and one-twelfth of
According to question, we have
⇒
⇒
⇒ 36x − 4x − 3x − x = 36 × 56 ⇒ 28x = 36 × 56
⇒
⇒
⇒
⇒ 36x − 4x − 3x − x = 36 × 56 ⇒ 28x = 36 × 56
⇒
Hence, the number is 72.
Solve: 3x = 2x+ 18
- a)9
- b)6
- c)0
- d)18
Correct answer is option 'D'. Can you explain this answer?
Solve: 3x = 2x+ 18
a)
9
b)
6
c)
0
d)
18
|
Ashwin Jain answered |
3x=2x+18
3x-2x=18 (transposing)
x= 18
3x-2x=18 (transposing)
x= 18
Can you explain the answer of this question below: The sum of two digits and the number formed by interchanging its digit is 110. If ten is subtracted from the first number, the new number is 4 more than 5 times of the sum of the digits in the first number. Find the first number.
- A:
46
- B:
48
- C:
64
- D:
84
The answer is c.
The sum of two digits and the number formed by interchanging its digit is 110. If ten is subtracted from the first number, the new number is 4 more than 5 times of the sum of the digits in the first number. Find the first number.
46
48
64
84
|
|
Aditi Saxena answered |
Let the unit digit be y & tens digit be x.
Original number = (10x+y)
After interchanging the digits
New number = (10y+x)
(10x+y) + (10y+x) = 110
11x +11y = 110
11(x+y)= 110
x+y = 110/11
x+y= 10 (1)
x= 10-y (2)
(10x+y) - 10 = 4+ 5(x+y)
(10x+y) - 10 = 4+ 5(10)
(10x+y) = 4+ 50+10
(10x+y) = 64
10(10-y) +y = 64
100-10y +y= 64
100 -9y = 64
-9y = 64-100
-9y = -36
y= 36/9= 4
y= 4
putting the value of y in eqn 2
x= 10-y
x= 10-4
x= 6
Hence , the first number is 6 & second number is 4.
Original Number is 10x+y = 10* 6+4= 60+4= 64
Solve: x = 4/5*(x+10)
- a)20
- b)10
- c)40
- d)30
Correct answer is option 'C'. Can you explain this answer?
Solve: x = 4/5*(x+10)
a)
20
b)
10
c)
40
d)
30
|
|
Malavika Basu answered |
x = 4/5*(x + 10)
=> x = 4x/5 + 8
=> x - 4x/5 = 8
=> (5x - 4x)/5 = 8
=> x = 8 * 5 = 40
Verification / Checking-
LHS = x = 40
RHS = 4/5*(x + 10) = 4/5*(40 + 10) = 4/5 * 50 = 40
Find the solution of 2x - 3 = 7 - a)3
- b)4
- c)5
- d)none of these
Correct answer is 'C'. Can you explain this answer?
Find the solution of 2x - 3 = 7
a)
3
b)
4
c)
5
d)
none of these
|
Arpita Basu answered |
by transposing,the signs will be change
2x-3=7
2x=7+3
2x=10
x=10/2
x=5.
The correct option is 5
Solve for x: 
- a)5
- b)10
- c)-14
- d)12
Correct answer is option 'A'. Can you explain this answer?
Solve for x:
a)
5
b)
10
c)
-14
d)
12
|
|
Amit Sharma answered |
We have, 
⇒
553x − 41 = 38x+34 ⇒ 15x = 75 ⇒ x = 75/15 = 5
David cuts a bread into two equal pieces and cuts one half into smaller pieces of equal size. Each of the small pieces is twenty grams in weight. If he has seven pieces of the bread all with him, how heavy is the original cake.- a)120 gm
- b)180 gm
- c)300 gm
- d)240 gm
Correct answer is option 'D'. Can you explain this answer?
David cuts a bread into two equal pieces and cuts one half into smaller pieces of equal size. Each of the small pieces is twenty grams in weight. If he has seven pieces of the bread all with him, how heavy is the original cake.
a)
120 gm
b)
180 gm
c)
300 gm
d)
240 gm
|
Sounak Sengupta answered |
D) 240 gm.
If she has 7 pieces totally, it means that one of those pieces is the uncut half, and the other half is cut into 6 pieces. Each of those 6 pieces has a weight of 20 gm which totally weighs 6*20= 120gm. If one half is 120 gm, then so is the other. Therefore the total weight of the cake is 120*2= 240 gm.
The distance between two mile stones is 230 km and two cars start simultaneously from the milestones in opposite directions and the distance between them after three hours is 20 km. If the speed of one car is less than that of other by 10 km/h, find the speed of each car.- a)25 km/h, 40 km/h
- b)40 km/h, 50 km/h
- c)20 km/h, 40 km/h
- d)30 km/h, 40 km/h
- e)None of these
Correct answer is option 'D'. Can you explain this answer?
The distance between two mile stones is 230 km and two cars start simultaneously from the milestones in opposite directions and the distance between them after three hours is 20 km. If the speed of one car is less than that of other by 10 km/h, find the speed of each car.
a)
25 km/h, 40 km/h
b)
40 km/h, 50 km/h
c)
20 km/h, 40 km/h
d)
30 km/h, 40 km/h
e)
None of these
|
|
Sarthak Singh answered |
Option d
Solve: 5t – 3 = 3t – 5
- a)-1
- b)1
- c)0
- d)2
Correct answer is option 'A'. Can you explain this answer?
Solve: 5t – 3 = 3t – 5
a)
-1
b)
1
c)
0
d)
2
|
Prerna Chavan answered |
5t-3=3t-5
5t-3t=-5+3
2t=-2
which gives t=-1
5t-3t=-5+3
2t=-2
which gives t=-1
Mary was counting down from 34 and Thomas was counting upwards simultaneously, the number starting from 1 and he was calling out only the odd numbers. Which common number will they call out at the same time if they were calling out at the same speed?
- a)20
- b)21
- c)22
- d)23
Correct answer is option 'D'. Can you explain this answer?
Mary was counting down from 34 and Thomas was counting upwards simultaneously, the number starting from 1 and he was calling out only the odd numbers. Which common number will they call out at the same time if they were calling out at the same speed?
a)
20
b)
21
c)
22
d)
23
|
|
Amit Kumar answered |
Which of the following is not a linear equation in one variable?- a)33z+ 5 = 0
- b)33 (x+y) = 0
- c)3x+5 = 0
- d)y+4 = 0
- e)none of these
Correct answer is option 'B'. Can you explain this answer?
Which of the following is not a linear equation in one variable?
a)
33z+ 5 = 0
b)
33 (x+y) = 0
c)
3x+5 = 0
d)
y+4 = 0
e)
none of these
|
Aditi answered |
The question is asked for finding the equation which is not a linear equation in "ONE VARIABLE" the B option is the answer because it contains two variables in it which is X and Y.
Arjun is twice as old as Shriya. Five years ago his age was three times Shriya’s age. Find their present ages.- a)15 years, 20 years
- b)10 years, 25 years
- c)10 years, 20 years
- d)None of these
Correct answer is option 'C'. Can you explain this answer?
Arjun is twice as old as Shriya. Five years ago his age was three times Shriya’s age. Find their present ages.
a)
15 years, 20 years
b)
10 years, 25 years
c)
10 years, 20 years
d)
None of these
|
Sarita Verma answered |
Let Arjun's age be x and shriya's age be y
A.T.Q.
x=2y
x-5=3 (y-5)
=>x-5=3y-15
=>2y-3y=-15+5
=>-y=-10
=>y=10
Now ,
x=2y
=>x=(2x10)
=>x=20
Therefore Arjun's age is 20 yrs and Shriya's age is 10 yrs.
Solve: 7x = 21- a)3
- b)2
- c)14
- d)none of these
Correct answer is option 'A'. Can you explain this answer?
Solve: 7x = 21
a)
3
b)
2
c)
14
d)
none of these
|
|
Poulomi Shah answered |
To solve the equation 7x = 21, we need to find the value of x that makes the equation true.
**Solution:**
Step 1: Divide both sides of the equation by 7 to isolate x.
7x/7 = 21/7
Simplifying, we have:
x = 3
Therefore, the value of x that satisfies the equation 7x = 21 is x = 3.
**Explanation:**
The equation 7x = 21 can be read as "7 times a number x is equal to 21." To solve for x, we need to find the value of x that satisfies this equation.
Dividing both sides of the equation by 7 is the first step in isolating x. By dividing by 7 on both sides, we cancel out the coefficient of x and obtain a simplified equation of x = 3.
This means that the value of x that makes the equation 7x = 21 true is x = 3. When we substitute x = 3 back into the original equation, we find that indeed 7 times 3 is equal to 21.
Therefore, the correct answer is option A: 3.
**Solution:**
Step 1: Divide both sides of the equation by 7 to isolate x.
7x/7 = 21/7
Simplifying, we have:
x = 3
Therefore, the value of x that satisfies the equation 7x = 21 is x = 3.
**Explanation:**
The equation 7x = 21 can be read as "7 times a number x is equal to 21." To solve for x, we need to find the value of x that satisfies this equation.
Dividing both sides of the equation by 7 is the first step in isolating x. By dividing by 7 on both sides, we cancel out the coefficient of x and obtain a simplified equation of x = 3.
This means that the value of x that makes the equation 7x = 21 true is x = 3. When we substitute x = 3 back into the original equation, we find that indeed 7 times 3 is equal to 21.
Therefore, the correct answer is option A: 3.
Sum of two numbers is 95. If one exceeds the other by 15, find the numbers.- a)40 and 60
- b)50 and 55
- c)50 and 60
- d)40 and 55
Correct answer is option 'D'. Can you explain this answer?
Sum of two numbers is 95. If one exceeds the other by 15, find the numbers.
a)
40 and 60
b)
50 and 55
c)
50 and 60
d)
40 and 55
|
Pooja Shah answered |
Let the number be x.
So, the other number is (x + 15).
(x + 15) + x = 95
2x + 15 = 95
2x = 95 - 15
2x = 80
x = 40
So, the numbers are 40 and 55.
So, the other number is (x + 15).
(x + 15) + x = 95
2x + 15 = 95
2x = 95 - 15
2x = 80
x = 40
So, the numbers are 40 and 55.
Solve for x : 6(3x+2)−5(6x−1) = 6(x−3)−5(7x−6)+12x- a)-1
- b)1
- c)0
- d)2
Correct answer is option 'A'. Can you explain this answer?
Solve for x : 6(3x+2)−5(6x−1) = 6(x−3)−5(7x−6)+12x
a)
-1
b)
1
c)
0
d)
2
|
Maya Tiwari answered |
We have,6(3x+2)−5(6x−1)
= 6(x−3)−5(7x−6)+12x
⇒18x+12−30x+5
= 6x−18−35x+30+12x
⇒ 5x=−5 ⇒ x=−1
In an equation the values of the expressions on the LHS and RHS are _______.- a)different
- b)not equal
- c)equal
- d)none of these
Correct answer is option 'C'. Can you explain this answer?
In an equation the values of the expressions on the LHS and RHS are _______.
a)
different
b)
not equal
c)
equal
d)
none of these
|
Shounak Goyal answered |
Explanation:
An equation is a mathematical statement in which two expressions are set equal to each other. The expressions on the left-hand side (LHS) and the right-hand side (RHS) of the equation are connected by an equal sign (=). The values of the expressions on the LHS and RHS are equal.
For example, consider the equation:
x + 2 = 7
Here, the LHS is x + 2 and the RHS is 7. The values of the expressions on the LHS and RHS are equal when x = 5.
Therefore, we can say that in an equation, the values of the expressions on the LHS and RHS are equal.
HTML:
An equation is a mathematical statement in which two expressions are set equal to each other. The expressions on the left-hand side (LHS) and the right-hand side (RHS) of the equation are connected by an equal sign (=). The values of the expressions on the LHS and RHS are equal.
For example, consider the equation:
x + 2 = 7
Here, the LHS is x + 2 and the RHS is 7. The values of the expressions on the LHS and RHS are equal when x = 5.
Therefore, we can say that in an equation, the values of the expressions on the LHS and RHS are equal.
HTML:
Explanation:
An equation is a mathematical statement in which two expressions are set equal to each other. The expressions on the left-hand side (LHS) and the right-hand side (RHS) of the equation are connected by an equal sign (=). The values of the expressions on the LHS and RHS are equal.
Example:
x + 2 = 7
Here, the LHS is x + 2 and the RHS is 7. The values of the expressions on the LHS and RHS are equal when x = 5.
Conclusion:
Therefore, we can say that in an equation, the values of the expressions on the LHS and RHS are equal.
A number whose seventh part exceeds its eighth part by 1, is _____.- a)58
- b)56
- c)64
- d)68
Correct answer is option 'B'. Can you explain this answer?
A number whose seventh part exceeds its eighth part by 1, is _____.
a)
58
b)
56
c)
64
d)
68
|
Priya Nair answered |
Let the number be x. According to question, we have
In the following number sequence, how many such even numbers are there which are exactly divisible by its immediate preceding number but not exactly divisible by its immediate following number?
3 8 4 1 5 7 2 8 3 4 8 9 3 9 4 2 1 5 8 2
- a)One
- b)Two
- c)Three
- d)Four
- e)None of these
Correct answer is option 'B'. Can you explain this answer?
In the following number sequence, how many such even numbers are there which are exactly divisible by its immediate preceding number but not exactly divisible by its immediate following number?
3 8 4 1 5 7 2 8 3 4 8 9 3 9 4 2 1 5 8 2
3 8 4 1 5 7 2 8 3 4 8 9 3 9 4 2 1 5 8 2
a)
One
b)
Two
c)
Three
d)
Four
e)
None of these
|
|
Shubham Sharma answered |
Let's analyze the sequence and determine how many even numbers satisfy the conditions:
Sequence: 3, 8, 4, 1, 5, 7, 2, 8, 3, 4, 8, 9, 3, 9, 4, 2, 1, 5, 8, 2
Step-by-Step Analysis:
-
Number 8 (2nd position):
- Preceding number: 3 → 8 is not divisible by 3.
- Following number: 4 → Condition not met, ignore this 8.
-
Number 4 (3rd position):
- Preceding number: 8 → 4 is not divisible by 8.
- Following number: 1 → Condition not met, ignore this 4.
-
Number 2 (7th position):
- Preceding number: 7 → 2 is not divisible by 7.
- Following number: 8 → Condition not met, ignore this 2.
-
Number 8 (8th position):
- Preceding number: 2 → 8 is divisible by 2.
- Following number: 3 → 8 is not divisible by 3.
- Condition met: Include this 8.
-
Number 4 (10th position):
- Preceding number: 3 → 4 is not divisible by 3.
- Following number: 8 → Condition not met, ignore this 4.
-
Number 8 (11th position):
- Preceding number: 4 → 8 is divisible by 4.
- Following number: 9 → 8 is not divisible by 9.
- Condition met: Include this 8.
-
Number 4 (15th position):
- Preceding number: 9 → 4 is not divisible by 9.
- Following number: 2 → Condition not met, ignore this 4.
-
Number 2 (16th position):
- Preceding number: 4 → 2 is not divisible by 4.
- Following number: 1 → Condition not met, ignore this 2.
-
Number 8 (19th position):
- Preceding number: 5 → 8 is not divisible by 5.
- Following number: 2 → Condition not met, ignore this 8.
-
Number 2 (20th position):
- This is the last number in the sequence, so no following number to check.
Conclusion:
The numbers that satisfy the conditions are the 8 at positions 8 and 11.
Thus, the correct answer is b) Two.
The sum of two digits and the number formed by interchanging its digit is 110. If ten is subtracted from the first number, the new number is 4 more than 5 times of the sum of the digits in the first number. Find the first number. - a) 46
- b) 48
- c) 64
- d) 84
Correct answer is option 'C'. Can you explain this answer?
The sum of two digits and the number formed by interchanging its digit is 110. If ten is subtracted from the first number, the new number is 4 more than 5 times of the sum of the digits in the first number. Find the first number.
a)
46
b)
48
c)
64
d)
84
|
|
Ananya Das answered |
Let the unit digit be y & tens digit be x.
Original number = (10x+y)
After interchanging the digits
New number = (10y+x)
(10x+y) + (10y+x) = 110
11x +11y = 110
11(x+y)= 110
x+y = 110/11
x+y= 10 (1)
x= 10-y (2)
(10x+y) - 10 = 4+ 5(x+y)
(10x+y) - 10 = 4+ 5(10)
(10x+y) = 4+ 50+10
(10x+y) = 64
10(10-y) +y = 64
100-10y +y= 64
100 -9y = 64
-9y = 64-100
-9y = -36
y= 36/9= 4
y= 4
putting the value of y in eqn 2
x= 10-y
x= 10-4
x= 6
Hence , the first number is 6 & second number is 4.
Original Number is 10x+y = 10* 6+4= 60+4= 64
The present age of Sahil’s mother is three times the present age of Sahil. After 5 years their ages will add to 66 years. Find their present ages.- a)28 years, 42 years
- b)14 years, 56 years
- c)28 years, 56 years
- d)14 years, 42 years
Correct answer is option 'D'. Can you explain this answer?
The present age of Sahil’s mother is three times the present age of Sahil. After 5 years their ages will add to 66 years. Find their present ages.
a)
28 years, 42 years
b)
14 years, 56 years
c)
28 years, 56 years
d)
14 years, 42 years
|
Sanjana Bose answered |
Let present age of sahil is 'x'
his mother age is '3x'
after five yearssahil's age is 'x+5'
his mother's age is '3x+5'
according to problem, given sum of their ages after five years is 66
⇒(x+5)+(3x+5)=66
4x+10=664x=66-10
4x=56
x=56/4
x=14sahil's age is x=14=14 years
sahil's mother age is 3x=3(14)= 42=42 years.
Solve: 5x−2(2x−7)=(3x−1)+7/2
- a)2
- b)3
- c)1/2
- d)23/4
Correct answer is 'D'. Can you explain this answer?
Solve: 5x−2(2x−7)=(3x−1)+7/2
a)
2
b)
3
c)
1/2
d)
23/4
|
|
Sanjana Bose answered |
5x-2(2x-7) = 2(3x-1)+7/2After opening the brackets5x-4x+14=6x-2+7/2Taking X to one side constants to other side6x+4x-5x= 14+2-7/2 or 5x= 16-7/2or 5x = (32-7)/2 or 5x= 25/2or x= 5/2
A number consists of two digits whose sum is 9. If 27 is subtracted from the original number, its digits are interchanged. Then the original number is _____.- a)53
- b)45
- c)92
- d)63
Correct answer is option 'D'. Can you explain this answer?
A number consists of two digits whose sum is 9. If 27 is subtracted from the original number, its digits are interchanged. Then the original number is _____.
a)
53
b)
45
c)
92
d)
63
|
Tanvi Singh answered |
Let units place digit be x. So tens place digit = 9 − x.
∴ The original number = 10(9-x)+x = 90-10x + x=90 - 9x Now, after interchanging the digits, the number formed = 10 (x) + 9 - x = 9x + 9
∴ According to question, we have 90 - 9x - 27 = 9x + 9
⇒ −18x = −54 ⇒ x = 3
So, the original number
= 90−9×3 = 63
8 men and 12 boys can finish a piece of work in 10 days while 6 men and 8 boys can finish the work in 14 days. find the time taking by 1 man alone and 1 boy alone to finish the same work.- a)120, 130
- b)140, 280
- c)240, 280
- d)100, 120
Correct answer is option 'B'. Can you explain this answer?
8 men and 12 boys can finish a piece of work in 10 days while 6 men and 8 boys can finish the work in 14 days. find the time taking by 1 man alone and 1 boy alone to finish the same work.
a)
120, 130
b)
140, 280
c)
240, 280
d)
100, 120
|
Mansi Tiwari answered |
The number 299 is divided into two parts in the ratio 5:8. The product of the numbers is_____.
- a)21140
- b)21294
- c)21160
- d)31294
Correct answer is option 'C'. Can you explain this answer?
The number 299 is divided into two parts in the ratio 5:8. The product of the numbers is_____.
a)
21140
b)
21294
c)
21160
d)
31294
|
|
Tanvi Singh answered |
Ratio of two parts = 5:8
Smaller number
Larger number
Larger number
So, the product of the number
= 115 × 184 = 21160
The sum of two digits and the number formed by interchanging its digit is 110. If ten is subtracted from the first number, the new number is 4 more than 5 times of the sum of the digits in the first number. Find the first number. - a) 46
- b) 48
- c) 64
- d) 84
Correct answer is 'C'. Can you explain this answer?
The sum of two digits and the number formed by interchanging its digit is 110. If ten is subtracted from the first number, the new number is 4 more than 5 times of the sum of the digits in the first number. Find the first number.
a)
46
b)
48
c)
64
d)
84
|
|
Sarita Verma answered |
Let the unit digit be y & tens digit be x.
Original number = (10x+y)
After interchanging the digits
New number = (10y+x)
(10x+y) + (10y+x) = 110
11x +11y = 110
11(x+y)= 110
x+y = 110/11
x+y= 10…………...(1)
x= 10-y……………(2)
(10x+y) - 10 = 4+ 5(x+y)
(10x+y) - 10 = 4+ 5(10)
(10x+y) = 4+ 50+10
(10x+y) = 64
10(10-y) +y = 64
100-10y +y= 64
100 -9y = 64
-9y = 64-100
-9y = -36
y= 36/9= 4
y= 4
putting the value of y in eqn 2
x= 10-y
x= 10-4
x= 6
Hence , the first number is 6 & second number is 4.
Original Number is 10x+y = 10 x 6+4= 60+4= 64
Solve: 6a+5=3a+14- a)3
- b)4
- c)5
- d)6
Correct answer is option 'A'. Can you explain this answer?
Solve: 6a+5=3a+14
a)
3
b)
4
c)
5
d)
6
|
EduRev Class 8 answered |
Given, 6a+5=3a+14
Transposing 3a to LHS and 5 to RHS:
Transposing 3a to LHS and 5 to RHS:
6a−3a=14−5
3a=9
Dividing by 3:
a=3
Therefore, option (A) is correct.
If 1/3 of a number is 10 less than the original number, then the number is_____.- a)30
- b)15
- c)10
- d)27
Correct answer is option 'B'. Can you explain this answer?
If 1/3 of a number is 10 less than the original number, then the number is_____.
a)
30
b)
15
c)
10
d)
27
|
Stuti Iyer answered |
Problem Statement:
If 1/3 of a number is 10 less than the original number, then the number is _____.
a) 30
b) 15
c) 10
d) 27
Solution:
Let us assume that the number is 'x'.
As per the given problem statement,
1/3 of the number is 10 less than the original number.
i.e. 1/3 x = x - 10
Multiplying both sides by 3
x = 3(x - 10)
x = 3x - 30
Bringing x terms to one side and constant terms to the other
2x = 30
Dividing by 2 on both sides
x = 15
Therefore, the original number is 15.
Answer: (b) 15
If 1/3 of a number is 10 less than the original number, then the number is _____.
a) 30
b) 15
c) 10
d) 27
Solution:
Let us assume that the number is 'x'.
As per the given problem statement,
1/3 of the number is 10 less than the original number.
i.e. 1/3 x = x - 10
Multiplying both sides by 3
x = 3(x - 10)
x = 3x - 30
Bringing x terms to one side and constant terms to the other
2x = 30
Dividing by 2 on both sides
x = 15
Therefore, the original number is 15.
Answer: (b) 15
- a)4
- b)8
- c)10
- d)6
Correct answer is option 'C'. Can you explain this answer?
a)
4
b)
8
c)
10
d)
6
|
Pavithra Pravin answered |
2x/3 + 1 = 7x/15 + 3
=> 2x/3 -- 7x/15 = 3 -- 1
=> 10x -- 7x/15 = 2
=> 3x/15 = 2
=> 3x = 2 × 15
=> 3x = 30
=> x = 30/3
=> x = 10
If (2/3)rd of a number is 20 less than the original number, then the number is_____. - a)60
- b)40
- c)80
- d)120
Correct answer is option 'A'. Can you explain this answer?
If (2/3)rd of a number is 20 less than the original number, then the number is_____.
a)
60
b)
40
c)
80
d)
120
|
|
Arpita Basu answered |
Let the number be x. According to question, we have 
Amina thinks of a number and subtracts 5/2 from it. She multiplies the result by 8. The result now obtained is 3 times the same number she thought of. What is the number?- a)2
- b)3
- c)4
- d)none of these
Correct answer is option 'C'. Can you explain this answer?
Amina thinks of a number and subtracts 5/2 from it. She multiplies the result by 8. The result now obtained is 3 times the same number she thought of. What is the number?
a)
2
b)
3
c)
4
d)
none of these
|
|
Ashwin Jain answered |
Let she thoughts the no x
according to question ,she subtract the 5/2 from the no.= x-5/2
now ,she multiply the result by 8 =8(x-5/2)
according to statement
3x = 8(x-5/2)
3x=8x -20
20=5x
x=4
she thought the no. as 4
The value of the expression on one side of the equality sign is _____ to the value of the expression on the other side.- a)different
- b)not equal
- c)equal
- d)none of these
Correct answer is option 'C'. Can you explain this answer?
The value of the expression on one side of the equality sign is _____ to the value of the expression on the other side.
a)
different
b)
not equal
c)
equal
d)
none of these
|
Kavya Saxena answered |
This says that any given equation says that it’s LHS is equal to RHS.
Solve: 4(y−2)+3=2(y+1)+5- a)6
- b)4
- c)3
- d)2
Correct answer is option 'A'. Can you explain this answer?
Solve: 4(y−2)+3=2(y+1)+5
a)
6
b)
4
c)
3
d)
2
|
|
EduRev Class 8 answered |
Expanding both sides:
4y−8+3=2y+2+5
4y−5=2y+7
Transposing 2y to LHS and −5 to RHS:
4y−2y=7+5
2y=12
Dividing by 2:
y=6
Therefore, option (A) is correct.
Solve the following linear equations:
4x + 5 = 9- a)4
- b)7
- c)1
- d)11
Correct answer is option 'C'. Can you explain this answer?
Solve the following linear equations:
4x + 5 = 9
4x + 5 = 9
a)
4
b)
7
c)
1
d)
11
|
|
EduRev Class 8 answered |
We have 4x + 5 = 9
⇒ 4x = 9 – 5 (Transposing 5 to RHS)
⇒ 4x = 4
⇒ x = 1 (Transposing 4 to RHS)
⇒ 4x = 9 – 5 (Transposing 5 to RHS)
⇒ 4x = 4
⇒ x = 1 (Transposing 4 to RHS)
Solve: 3x−7=2x+5- a)7
- b)8
- c)12
- d)5
Correct answer is option 'C'. Can you explain this answer?
Solve: 3x−7=2x+5
a)
7
b)
8
c)
12
d)
5
|
|
EduRev Class 8 answered |
Given, 3x−7=2x+5
Transposing 2x to LHS:
3x−2x−7=5
x−7=5
Transposing −7 to RHS:
x=5+7
x=12
Therefore, option (C) is correct.
Chapter doubts & questions for Linear Equations in One Variable - Advance Learner Course: Mathematics (Maths) Class 7 2025 is part of Class 7 exam preparation. The chapters have been prepared according to the Class 7 exam syllabus. The Chapter doubts & questions, notes, tests & MCQs are made for Class 7 2025 Exam. Find important definitions, questions, notes, meanings, examples, exercises, MCQs and online tests here.
Chapter doubts & questions of Linear Equations in One Variable - Advance Learner Course: Mathematics (Maths) Class 7 in English & Hindi are available as part of Class 7 exam.
Download more important topics, notes, lectures and mock test series for Class 7 Exam by signing up for free.
Advance Learner Course: Mathematics (Maths) Class 7
41 videos|45 docs|9 tests
|
Signup to see your scores go up within 7 days!
Study with 1000+ FREE Docs, Videos & Tests
10M+ students study on EduRev
|
© EduRev
|
Education Revolution
|
|
Signup to see your scores
go up
within 7 days!
within 7 days!
Takes less than 10 seconds to signup