Linear Equations in One Variable Exercise 2.2
NCERT solutions for Class 8 Maths Linear Equations in One Variable
NCERT Solutions for Class 8 Maths Linear Equations in One Variable
Class –VIII Mathematics(Ex. 2.2)
1. If you subtract 
from a number and multiply the result by 
you get 
What is the number?
Ans. Let the number be 
According to the question,
]
Hence, the required number is 
2. The perimeter of a rectangular swimming pool is 154 m. Its length is 2 m more than twice its breadth. What are the length and breadth?
Ans. Let the breadth of the pool be 
m.
Then, the length of the pool = 
m
Perimeter = 
154 = 
m
Hence, length of the pool = 
= 50 + 2 = 52 m
And, breadth of the pool = 25 m.
3. The base of an isosceles triangle is 
cm. The perimeter of the triangle is 
cm. What is the length of either of the remaining equal sides?
Ans. Let each of equal sides of an isosceles triangle be cm.
Perimeter of a triangle = Sum of all three sides
from both the sides]
cm
Hence, each equal side of an isosceles triangle is 
cm.
4. Sum of two numbers is 95. If one exceeds the other by 15, find the numbers.
Ans. Sum of two number = 95
Let the first number be 
then another number be 
.
According to the question, 
Hence, the first number = 40
And another number = 40 + 15 = 55.
5. Two numbers are in the ratio 5 : 3. If they differ by 18, what are the numbers?
Ans. Let the two numbers be 
and 
According to question, 
Hence, first number = 
= 45 and second number = 
= 27.
6. Three consecutive integers add up to 51. What are these integers?
Ans. Let the three consecutive integers be 
and 
According to the question, 
Hence, first integer = 16,
second integer = 16 + 1 = 17 and
third integer = 16 + 2 = 18.
7. The sum of three consecutive multiples of 8 is 888. Find the multiples.
Ans. Let the three consecutive multiples of 8 be 
and 
According to question, 
Hence, first multiple of 8 = 288,
second multiple of 8 = 288 + 8 = 296 and third multiple of 8 = 288 + 16 = 304.
8. Three consecutive integers are such that when they are taken in increasing order and multiplied by 2, 3 and 4 respectively, they add up to 74. Find these numbers.
Ans. Let the three consecutive integers be and
According to the question, 
Hence first integer = 7, second integer
= 7 + 1 = 8 and third integer = 7 + 2 = 9.
NCERT Solutions for Class 8 Maths Exercise 2.2
9. The ages of Rahul and Haroon are in the ratio 5 : 7. Four years later the sum of their ages will be 56 years. What are their present ages?
Ans. Let the present ages of Rahul and Haroon be 
years and 
years respectively.
According to condition,
Hence, present age of Rahul = 
= 20 years and present age of Haroon
= 
= 28 years.
10. The number of boys and girls in a class are in the ratio 7 : 5. The number of boys is 8 more than the number of girls. What is the total class strength?
Ans. Let the number of girls be
Then, the number of boys = 
According to the question,
to L.H.S. and 40 to R.H.S.]
]
Hence the number of girls = 20 and number of boys = 20 + 8 = 28.
11. Baichung’s father is 26 years younger than Baichung’s grandfather and 29 years older than Baichung. The sum of the ages of all the three is 135 years. What is the age of each one of them?
Ans. Let Baichung’s age be years, then Baichung’s father’s age = 
years and Baichung’s granddaughter’s age = 
years.
According to condition, 
years
Hence, Baichung’s age = 17 years, Baichung’s father’s age = 17 + 29
= 46 years
And Baichung’s granddaughter’s age
= 17 + 29 + 26 = 72 years.
NCERT Solutions for Class 8 Maths Exercise 2.2
12. Fifteen years from now Ravi’s age will be four times his present age. What is Ravi’s present age?
Ans. Let Ravi’s present age be years.
After fifteen years, Ravi’s age = 
years.
Fifteen years from now, Ravi’s age = 
years.
According to question, 
to L.H.S.]
years
Hence, Ravi’s present age be 5 years.
NCERT Solutions for Class 8 Maths Exercise 2.2
13. A rational number is such that when you multiply it by 
and add
to the product, you get 
What is the number?
Ans. Let the rational number be
According to the question, 
from both sides]
Hence, the rational number is 
NCERT Solutions for Class 8 Maths Exercise 2.2
14. Lakshmi is a cashier in a bank. She has currency notes of denominations ` 100, `50 an`10 respectively. The ratio of the number of these notes is 2 : 3 : 5. The total cash with Lakshmi is `4,00,000. How many notes of each denomination does she have?
Ans. Let number of notes be 
and 
According to question, 
Hence, number of denominations of ` 100 notes = 
= 2000
Number of denominations of ` 50 notes = 
= 3000
Number of denominations of ` 10 notes = 
= 5000
Therefore, required denominations of notes of ` 100, ` 50 and ` 10 are 2000, 3000 and 5000 respectively.
NCERT Solutions for Class 8 Maths Exercise 2.2
15. I have a total of `300 in coins of denomination `1, `2 and `5. The number of `2 coins is 3 times the number of `5 coins. The total number of coins is 160. How many coins of each denomination are with me?
Ans. Total sum of money = ` 300
Let the number of ` 5 coins be number of ` 2 coins be 
and number of ` 1 coins be 
According to question, 
Hence, the number of coins of ` 5 denomination = 20
Number of coins of ` 2 denomination = 
= 60
Number of coins of ` 1 denomination = 
= 160 – 80 = 80
NCERT Solutions for Class 8 Maths Exercise 2.2
16. The organizers of an essay competition decide that a winner in the competition gets a prize of `100 and a participant who does not win, gets a prize of `25. The total prize money distributed is `3,000. Find the number of participants is 63.
Ans. Total sum of money = ` 3000
Let the number of winners of ` 100 be
And those who are not winners = 
According to the question, 
Hence the number of winner is 19.