Selina Textbook Solutions: Percent and Percentage | Mathematics Class 8 ICSE PDF Download

 Page 1


7. Percent and Percentage 
EXERCISE 7(A) 
Question 1. 
Evaluate : 
(i) 55% of 160 + 24% of 50 – 36% of 150 
(ii) 9.3% of 500 – 4.8% of 250 – 2.5% of 240 
Solution: 
 
Question 2. 
(i) A number is increased from 125 to 150 ; find the percentage increase. 
(ii) A number is decreased from 125 to 100 ; find the percentage decrease. 
Solution: 
 
Question 3. 
Find : 
(i) 45 is what percent of 54 ? 
(ii) 2.7 is what percent of 18 ? 
Page 2


7. Percent and Percentage 
EXERCISE 7(A) 
Question 1. 
Evaluate : 
(i) 55% of 160 + 24% of 50 – 36% of 150 
(ii) 9.3% of 500 – 4.8% of 250 – 2.5% of 240 
Solution: 
 
Question 2. 
(i) A number is increased from 125 to 150 ; find the percentage increase. 
(ii) A number is decreased from 125 to 100 ; find the percentage decrease. 
Solution: 
 
Question 3. 
Find : 
(i) 45 is what percent of 54 ? 
(ii) 2.7 is what percent of 18 ? 
Solution: 
 
Question 4. 
(i) 252 is 35% of a certain number, find the number. 
(ii) If 14% of a number is 315 ; find the number. 
Solution: 
 
 
Page 3


7. Percent and Percentage 
EXERCISE 7(A) 
Question 1. 
Evaluate : 
(i) 55% of 160 + 24% of 50 – 36% of 150 
(ii) 9.3% of 500 – 4.8% of 250 – 2.5% of 240 
Solution: 
 
Question 2. 
(i) A number is increased from 125 to 150 ; find the percentage increase. 
(ii) A number is decreased from 125 to 100 ; find the percentage decrease. 
Solution: 
 
Question 3. 
Find : 
(i) 45 is what percent of 54 ? 
(ii) 2.7 is what percent of 18 ? 
Solution: 
 
Question 4. 
(i) 252 is 35% of a certain number, find the number. 
(ii) If 14% of a number is 315 ; find the number. 
Solution: 
 
 
Question 5. 
Find the percentage change, when a number is changed from : 
(i) 80 to 100 
(ii) 100 to 80 
(iii) 6.25 to 7.50 
Solution: 
 
Question 6. 
An auctioneer charges 8% for selling a house. If a house is sold for Rs.2, 30, 500; find 
the charges of the auctioneer. 
Solution: 
Page 4


7. Percent and Percentage 
EXERCISE 7(A) 
Question 1. 
Evaluate : 
(i) 55% of 160 + 24% of 50 – 36% of 150 
(ii) 9.3% of 500 – 4.8% of 250 – 2.5% of 240 
Solution: 
 
Question 2. 
(i) A number is increased from 125 to 150 ; find the percentage increase. 
(ii) A number is decreased from 125 to 100 ; find the percentage decrease. 
Solution: 
 
Question 3. 
Find : 
(i) 45 is what percent of 54 ? 
(ii) 2.7 is what percent of 18 ? 
Solution: 
 
Question 4. 
(i) 252 is 35% of a certain number, find the number. 
(ii) If 14% of a number is 315 ; find the number. 
Solution: 
 
 
Question 5. 
Find the percentage change, when a number is changed from : 
(i) 80 to 100 
(ii) 100 to 80 
(iii) 6.25 to 7.50 
Solution: 
 
Question 6. 
An auctioneer charges 8% for selling a house. If a house is sold for Rs.2, 30, 500; find 
the charges of the auctioneer. 
Solution: 
Total number of oranges = 800 
 
Question 8. 
A cistern contains 5 thousand litres of water. If 6% water is leaked. Find how many litres 
of water are left in the cistern. 
Solution: 
 
Question 7. 
Out of 800 oranges, 50 are rotten. Find the percentage of good oranges. 
Solution: 
Solution: 
 
Question 9. 
A man spends 87% of his salary. If he saves Rs.325 ; find his salary. 
Page 5


7. Percent and Percentage 
EXERCISE 7(A) 
Question 1. 
Evaluate : 
(i) 55% of 160 + 24% of 50 – 36% of 150 
(ii) 9.3% of 500 – 4.8% of 250 – 2.5% of 240 
Solution: 
 
Question 2. 
(i) A number is increased from 125 to 150 ; find the percentage increase. 
(ii) A number is decreased from 125 to 100 ; find the percentage decrease. 
Solution: 
 
Question 3. 
Find : 
(i) 45 is what percent of 54 ? 
(ii) 2.7 is what percent of 18 ? 
Solution: 
 
Question 4. 
(i) 252 is 35% of a certain number, find the number. 
(ii) If 14% of a number is 315 ; find the number. 
Solution: 
 
 
Question 5. 
Find the percentage change, when a number is changed from : 
(i) 80 to 100 
(ii) 100 to 80 
(iii) 6.25 to 7.50 
Solution: 
 
Question 6. 
An auctioneer charges 8% for selling a house. If a house is sold for Rs.2, 30, 500; find 
the charges of the auctioneer. 
Solution: 
Total number of oranges = 800 
 
Question 8. 
A cistern contains 5 thousand litres of water. If 6% water is leaked. Find how many litres 
of water are left in the cistern. 
Solution: 
 
Question 7. 
Out of 800 oranges, 50 are rotten. Find the percentage of good oranges. 
Solution: 
Solution: 
 
Question 9. 
A man spends 87% of his salary. If he saves Rs.325 ; find his salary. 
Question 10. 
(i) A number 3.625 is wrongly read as 3.265; find the percentage error. 
(ii) A number 5.78 x 10
3
 is wrongly written as 5.87 x 10
3
; find the percentage error 
Solution: 
 
Question 11. 
In an election between two candidates, one candidate secured 58% of the votes polled 
and won the election by 18, 336 votes. Find the total number of votes polled and the 
votes secured by each candidate. 
Solution: