A merchant bought two watches for ₹9,000 each. He sold one watch at a loss of 10%. At what price (in ₹) should he sell the other watch to earn a profit of 18% overall?

Correct option is D

Given:
Cost price of each watch = Rs 11520
Loss of one watch = 10%
Gain to be earn on other watch=18%
Formula Used:
Profit Percentage = $$\frac{ Profit}{Cost \ Price} \times 100$$​​
SP = CP + Profit
Solution:
CP of one watch = Rs. 9000
First watch is sold at 10% loss
SP = 9000 - 10%of 9000 = Rs. 8100
Overall profit to be gain on both watches should be 18%
Profit = 18% of 18000
= Rs. 3240
Total selling price of both watches = Rs. 18000 + 3240 = Rs. 21240
Second watch should be sold at Rs.21240 - 8100 = Rs. 13140