If the cost price of 30 books is same as the selling price of 20 books, then the gain percentage is:
Show answer & explanation
Correct answer: C
Explanation
The correct answer is option 3 i.e 50%.
Let the cost price of 1 book be ₹1.
Then, the cost price of 30 books = ₹30
Given: Selling price of 20 books = ₹30
So, selling price of 1 book = ₹30 ÷ 20 = ₹1.5
Profit on one book = SP - CP = ₹1.5 - ₹1 = ₹0.5
Profit % = (Profit ÷ CP) × 100 = (0.5 ÷ 1) × 100 = 50%