Correct Answer - Option 2 : 25%
Given
SP of 15 books - CP of 15 books = SP of 3 books
SP of 15 books - SP of 3 books = CP of 15 books
SP of 12 books = CP of 15 books
Formula
%Profit = [(SP – CP)/CP] × 100
Calculation
Let, CP of 1 book be X Rs.
Then CP of 12 books = 12X Rs.
And SP of 12 books = 15X
%Profit = [(15X – 12X)/12X] x100
⇒ (3/12) x 100
⇒ 25%
∴ Profit% in the given transaction is 25%