Q. The marked price of a clock is 160 Rs, after two successive discounts a customer buys it for 122.40 Rs. If first discount is 10%, then what would be the second discount:
Answer:
15%
Notes: Given that the list Price = 160 Rs.
After 10% discount Selling Price $ = \frac{90}{100}\times 160 = 144 Rs.$
Now, Let the other discount = x%
$ \therefore \frac{100-x}{100}\times 144 = 122.40 Rs. $
$ => 100-x = \frac{12240}{144}$
$ => 100 – x = 85$
$ => x = 100 – 85 = 15\%$
Hence option [C] is correct answer.