In this task, you need to answer the given multiple-choice question on the gain. Gain is the value by which to multiply the input. Classify your answers into 'a', 'b', 'c', 'd', and 'e'.

[EX Q]: Problem: john and jane went out for a dinner and they ordered the same dish . both used a 10 % discount coupon . john paid a 15 % tip over the original price of the dish , while jane paid the tip over the discounted price for the coupon . if john paid $ 0.63 more than jane , what was the original price of the dish ? 
Options: a ) 24 , b ) 34.8 , c ) 37.8 , d ) 42 , e ) 84
[EX A]: d

[EX Q]: Problem: a number exceeds 20 % of itself by 40 . the number is ? 
Options: a ) 50 , b ) 60 , c ) 80 , d ) 320 , e ) none
[EX A]: a

[EX Q]: Problem: if the radius of a circle is decreased by 50 % , find the percentage decrease in its area . 
Options: a ) 25 % , b ) 50 % , c ) 75 % , d ) 95 % , e ) none of them
[EX A]:
c