If the selling price of 10 articles is the same as the cost price of 12 articles, find the gain percent.

Correct option is B

Ans. (b)
Sol.
Let the cost price (C.P.) of 1 article = ₹1
So, C.P. of 12 articles = ₹12
Given:
Selling Price (S.P.) of 10 articles = C.P. of 12 articles = ₹12
⇒ S.P. of 1 article = ₹12 ÷ 10 = ₹1.20
Now,
C.P. of 1 article = ₹1
S.P. of 1 article = ₹1.20
Gain = S.P. – C.P. = ₹1.20 – ₹1 = ₹0.20
Gain % = (Gain / C.P.) × 100 = (0.20 / 1) × 100 = 20%