Question

The selling price of 10 books is equal
to the cost price of 11
books. What is the gain % ?
​

Answer 1

let cp of 1 book be x

cp of 11 books = 11x = sp of 10 books

cp of 10 books = 10x

gain = sp - cp

= 11x - 10x

= x

gain%= gain/cp × 100

= x/10x × 100

= 1/10×100

= 10 %

gain % = 10%