Page 85 - ICSE Math 8

Example 2: There were two candidates in an election. One candidate got 48% votes and lost by 480 votes.
Find the total number of votes polled.
Solution: Let the total number of votes polled be x.
Difference in number of votes = 480
(52 – 48)% of x = 480 or, 4% of x = 480
4 480 × 100
⇒ 100 × x = 480 ⇒ x = 4 ⇒ x = 12,000

∴ Total number of votes polled was 12,000.

Finding the Number from a Given Percentage of the Number Maths Info

Write the given percentage as a fraction of 100 and then divide the given 100% of a number is the number
number by this fraction to get the required number. itself.

Example 3: Rahul spent 48% of his salary and deposited the remaining money in a bank. If he deposited
` 18,720 money in the bank, how much money did he spend?
Solution: Let the total money be ` x.
Money deposited in bank = (100 – 48)% Try These
= 52% of total money 1. Find the number whose 26% is 41.6.
According to the question, 2. A fruit seller bought 14 dozen
52 bananas. He did not sell 42 bananas
52% of x = 18,720 ⇒ 100 × x = 18,720 as they were spoilt. What percentage
18,720 × 100 of the total bananas did he sell?
⇒ x = 52 = 36,000
Money spent = ` (36,000 – 18,720) = ` 17,280

Example 4: Among two chocolate manufacturing companies, company A sold 38% of the total chocolates,
which was 4,680 chocolates less than what was sold by company B. Find the total number of
chocolates sold.
Solution: Let the total number of chocolates sold be x.
Chocolates sold by company A = 38%
Chocolates sold by company B = (100 – 38)% = 62%
According to the question,
24
62% of x – 38% of x = 4,680 ⇒ 24% of x = 4,680 ⇒ 100 × x = 4,680
⇒ x = 19,500 chocolates

Example 5: Kiran’s income is 25% less than that of Rama’s. How much per cent is Rama’s income more
than that of Kiran’s?
Solution: Let Rama’s income be ` 100.
Since Kiran’s income is 25% less than that of Rama’s,
\ Kiran’s income = ` 75
If Kiran’s income is ` 75, Rama’s income = ` 100
100
If Kiran’s income is ` 1, Rama’s income = `
75
100 400
If Kiran’s income is ` 100, Rama’s income = ` × 100 = `
75 3
400 1
\ Rama’s income is 3 – 100 % = 33 % more than Kiran’s income.
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