SSC Sample Paper Mock Test-2 SSC CGL Tear-II Paper-1

The list price of a watch is Rs. 160. After two successive discounts, it is sold for Rs. 122.40. If the first discount is 10%, what is the rate of second discount?

A) 10%

B) 15%

C) 20%

D) 22%

Correct Answer: B

Solution :

List price = Rs. 160

Let second discount be r%.

\[\therefore \]Cost after second discount

\[=\frac{(100-r)}{100}\times \frac{(100-10)}{100}\times 160=\frac{(100-r)}{100}\times \frac{90}{100}\times 160\]

\[=(100-r)\times \frac{36}{25}\]

But cost is Rs. 122.40

Given, Rs. 122.40 \[(100-r)\times \frac{36}{25}\]

\[\frac{122.40\times 25}{36}=100-r\]

\[\Rightarrow \] \[85=100-r\]

\[\Rightarrow \] \[r=100-85=15%\]