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Ratios to Per cents

Let us take an example, suppose the amount of `350 is divided among three friends A, B and C in
the ratio 2 : 3 : 5. How much amount in per cent will each friend get?

Here, the total amount has been divided into 2 + 3 + 5 = 10 parts between three friends A, B, and C.
Friend A gets 2 out of 10 parts of `350.

2  70 
So, A gets × `350 = `70, which is  × 100 % = 20% of the total amount.

10  350 
3  105 
Similarly, B gets × `350 = `105, which is  × 100 % = 30% of the total amount.

10  350 
5  175 
And C gets × `350 = `175, which is  × 100 % = 50% of the total amount.

10  350 
Increase or Decrease as Percentage Think and Answer

`3000 is divided among Sunil,
Percentage change = Decrease /Increase in the value × 100% Anil and Raj, so that Sunil gets
Original value three parts, Anil four parts
and Raj five parts. How much

= (New value–Original value) × 100% money will each get? What
Original value will it be in percentage?

Example 15: Increase 80 by 45%.
45
Solution: We have, 45% of 80 = × 80 = 36
100

\ Increased Value = 80 + 36 =116
Example 16: Decrease 60 by 15%.

Solution: We have,

15
15% of 60 = × 60 = 9
100
\ Decreased Value = 60 – 9 = 51

Example 17: The price of sugar has decreased from `56 per kg to `54 per kg. Find the percentage
of decrease in price.
Solution: Original price of sugar = `56

Current price of sugar = `54

Decrease in price = `56 − `54 = `2
 decrease in value   2  25 4
Percentage decrease in price =  original value × 100 % =   56 × 100 % = 7 % = 3 %





7
4
Thus, the price of sugar decreases by 3 %.
7
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