Question

Cp of 40 Apples is equal to sp of 30 apples. find gain percentage?

Answer 1

Let cost price of each apple be 1 rupee

Such that, 
Cost price of 40 apples = 40 rupees
Selling price of 30 apples = 40 rupees

As given CP of 40 apples = SP of 30 apples

Gain % = (40-30/30) × 100
             = 10/30 ×100
             = 1000/30
             = 100/3
             = 33.33%

Therefore, Gain % = 33.33%