Percentage (Exercise 11.4) RD Sharma Solutions | Mathematics (Maths) Class 7 PDF Download

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1. Find each of the following: 
(i) 7% of Rs 7150 
(ii) 40% of 400kg 
(iii) 20% of 15.125liters 
(iv) 3 1/3 % of 90km 
(v) 2.5% of 600meters 
 
Solution: 
(i) Given 7% of Rs 7150 
= (7/100) × 7150 
= Rs 500.50 
 
(ii) Given 40% of 400kg 
= (40/100) × 400 
= 160kg 
 
(iii) Given 20% of 15.125liters 
= (20/100) × 15.125 
= 3.025liters 
 
(iv) Given 3 1/3 % of 90km 
We know that 3 1/3 = (10/3) 
= (10/300) × 90 
= 3km 
 
(v) Given 2.5% of 600 meters 
= (2.5/100) x 600 
= 15 meters 
 
2. Find the number whose 12 ½ % is 64. 
 
Solution: 
Let the required number be x 
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1. Find each of the following: 
(i) 7% of Rs 7150 
(ii) 40% of 400kg 
(iii) 20% of 15.125liters 
(iv) 3 1/3 % of 90km 
(v) 2.5% of 600meters 
 
Solution: 
(i) Given 7% of Rs 7150 
= (7/100) × 7150 
= Rs 500.50 
 
(ii) Given 40% of 400kg 
= (40/100) × 400 
= 160kg 
 
(iii) Given 20% of 15.125liters 
= (20/100) × 15.125 
= 3.025liters 
 
(iv) Given 3 1/3 % of 90km 
We know that 3 1/3 = (10/3) 
= (10/300) × 90 
= 3km 
 
(v) Given 2.5% of 600 meters 
= (2.5/100) x 600 
= 15 meters 
 
2. Find the number whose 12 ½ % is 64. 
 
Solution: 
Let the required number be x 
 
 
 
 
 
 
 
Then according to the question, 12 ½ % × x = 64 
= 12.5 % × x = 64 
= (12.5/ 100) × x = 64 
x = (64 x 100)/ 12.5 
x = 64 × 8 = 512 
Therefore 512 is the number whose 12 ½ % is 64. 
 
3. What is the number, 6 ¼ % of which is 2? 
 
Solution: 
Let the required number be x 
Then according to the question, 6 ¼ % × x = 64 
= 6.25 % × x = 2 
= (6.25/100) × x = 2 
x = (2 × 100)/ 6.25 
x = 2 × 16 = 32 
Therefore 32 is the number whose 6 ¼ % is 32. 
 
4. If 6 is 50% of a number, what is that number? 
 
Solution: 
Let the required number be x 
Given that 50 % of x = 6 
(50/100) × x = 6 
x = (6 × 100)/ 50 
x = 12 
The required number is 12