After getting two successive discounts, a shirt with a list price of Rs. 300 is available at Rs. 210. if the second discount is 12.5%, find the first discount.  Choose the correct choice from the following options.
A) 15%
B) 20%
C) 25%
D) 12.5%
E) None of these
Explanation :   Solution: let the first discount be x%.   Then, 87.5% of(100-x)% of 300 =210.   87.5/100 * (100-x)/100 of 300 =210 ==&gt; 100-x = 210*100*100/(300*87.5)= 
<gadget id="calculator">210*100*100/(300*87.5)</gadget>
<output>80</output>
80==&gt; x = (100-80)= 
<gadget id="calculator">(100-80)</gadget>
<output>20</output>
20.   .'. First discount= 20%.   Answer : 20%
<result>B</result>
After getting two successive discounts, a shirt with a list price of Rs. 300 is available at Rs. 210. if the second discount is 12.5%, find the first discount.