DRDO Multi tasking staff Model paper 10

Short trick:
Cost price = 850 × 0.96 ÷ 1.2 = Rs. 680
Detailed solution:
Given,
Marked price of a shirt = Rs. 850
Discount percentage = 4%
Selling price of a shirt after discount = 850 - 850 × (4/100) = 816
Selling price of a shirt after discount = Rs. 816
Profit percentage = 20%
Profit percentage = [(S.P - C. P)/C.P] × 100
⇒ 20 = [(816 - C.P)/C.P] × 100
⇒ C.P = 4080 - 5C.P
⇒ C.P = 680
∴ Cost price of a shirt is Rs. 680.