The ratio of cost price and selling price of an article is 20 : 21. What is the gain per cent on it? A. 5% B. 5(1/2)% C. 6% D. 6(1/4)%

Question

The ratio of cost price and selling price of an article is 20 : 21. What is the gain per cent on it? 

A. 5%

B. \(5\frac{1}{2}\%\)

C. 6%

D. \(6\frac{1}{4}\%\)

Answer 1

Let x be the common multiple 

CP = 20x 

SP = 21x 

Gain = SP – CP 

= 21x – 20x 

= x

Gain Percent = \(Gain\%=\frac{Gain\,\times\,100}{CP}\)

= \(\frac{x\,\times\,100}{20x}\)

= 5%