Bihar Police Constable Model Paper 4

Given:
Cost price of 12 potatoes = Selling price of 10 potatoes
Concept:
Percentage profit = Profit / CP × 100
Profit = SP - CP
Calculation:
CP × 12 potatoes = SP × 10 potatoes
CP/SP = 10/12
Profit = 12 - 10 ⇒ 2
∴ Percentage profit = 2/10 × 100
= 20%