DRDO Multi tasking staff Model paper 1

Tips & Tricks
Let cost price of an article be Rs. A
Profit percentage = 10% = loss percentage
Then,
⇒ 10 = [(A - S.P)/A] × 100
⇒ A = 10A - 10S.P
⇒ S.P = 9A/10
Selling price of an article = Rs. 270
Given,
⇒ 9A/10 = 270
⇒ A = 300
∴ Cost price of an article is Rs. 300.