# Percentage

1. If 25% of x = y, then y% of 40 is same as :

A. 25% of x

B. 20% of x

C. 5% of x

D. 10% of x

Explanation:

25% of x = y
=> (25/100) * x = y
y% of 40 =(y/100) x 40
= [(25x/100)  / 100] x 40
= 10x/100 = 10% of x

2. The value of a motor depreciates at the rate of 10% every year. It was purchased 3 years ago. If its present value is Rs. 5832, its purchase price was :

A. 10000

B. 8000

C. 12000

D. 8500

Explanation:

Purchase price = Rs. 5832(1−10/100)^3
= Rs. [5832 * (10/9) * (10/9 )* (10/9)]
= Rs.8000

3. If the price of a book is first decreased by 25% and then increased by 20%, then the net change in the price will be:

A. 10

B. 20

C. 30

D. 40

Explanation:

Let the original price be 100.

New final price  = 120 % of (75 % of 100)
= [(120/100) * (75/100) * 100]
= 90
Hence, Decrease = 10%

4. If A's height is 40% less than that of B, how much percent B's height is more than that of A?

A. 76.67%

B. 83.67%

C. 66.67%

D. 86.66%

Explanation:

If B's height is 100, then A's height is 60.
Excess of B's height over A's = (100 - 60) = 40
In % = (40/60)*100 = 66.67%

5. What percent of 6.4 kg is 16 gms ?

A. .25%

B. .5%

C. .75%

D. 1%