Page 91 - Maths Skills - 7

Comparing Quantities 89

3. Express each of the following as a fraction.
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(i) 30% (ii) 12 % (iii) 1.45% (iv) 0.5% (v) 0.24%
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1 2
(vi) 3 % (vii) 9% (viii) 25 % (ix) 140%
4 3
4. Find the value of.
1 1
(i) 25% of `100 (ii) 4 % of ` 180 (iii) 2.25% of 1000 m (iv) 15 % of 18
2 3

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(v) 0.5% of 250 km (vi) 20% of 12.25 km (vii) 140% of 5 kg (viii) 3 % of 60 litres
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5. Express each of the following fractions or mixed numbers into a per cent.

(i) 51 (ii) 2 3 (iii) 75 (iv) 6 1 (v) 1
100 5 40 4 7
6. Express each of the following decimals as a per cent.

(i) 0.04 (ii) 2.35 (iii) 7.50 (iv) 0.23 (v) 0.0008

(vi) 7.25 (vii) 0.07 (viii) 1.204 (ix) 15.2

7. Express each of the following ratios as a per cent.
(i) 1 : 5 (ii) 2 : 3 (iii) 25 : 75 (iv) 20 : 25 (v) 11 : 125

8. Out of an income of `1500, Sita spends ` 575. What per cent of her income does she save?
9. If y% of 250 is 21, find the value of y.

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10. Find the number whose 3 % is 13.
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11. Find the number whose 0.05% is 200.

12. Find the number whose 10% is 5.
13. Nishant obtained 40 marks out of 80. What per cent marks did he get?
14. A basket contains 120 oranges. 25 oranges were distributed among the students. Find the percentage of
oranges left in the basket.

15. What per cent is each of the following?
(i) ` 100 of ` 500? (ii) 160 metres of 5 km? (iii) 75 paise of ` 8?

(iv) 0.5 of 5? (v) 450 grams of 2.75 kg? (vi) 12 minutes of 3 hours?

INCREASE OR DECREASE PER CENT
When there is a increase or decrease in a certain quantity, then we understand it in a better way if it is expressed in
per cent. For example, number of students of a school increased from 2000 to 2500. So this increase can be better
understood if we say that the number of students increased by 25%. We can calculate the increase or decrease in
per cent (%) as follows:

 Increased value   Decreased value 
(i) Increase % =  ×100 (ii) Decrease % =  ×100 

 Original value   Original value 
Let’s learn through examples.