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'.

Q: Problem: increasing the original price of an article by 6 percent and then increasing the new price by 6 percent is equivalent to increasing the original price by 
Options: a ) 12.1 % , b ) 12.36 % , c ) 12.94 % , d ) 13.65 % , e ) 14.56 %

A: b
****
Q: Problem: fox jeans regularly sell for $ 10 a pair and pony jeans regularly sell for $ 18 a pair . during a sale these regular unit prices are discounted at different rates so that a total of $ 9 is saved by purchasing 5 pairs of jeans : 3 pairs of fox jeans and 2 pairs of pony jeans . if the sum of the two discounts rates is 22 percent , what is the discount rate on pony jeans ? 
Options: a ) 9 % , b ) 10 % , c ) 11 % , d ) 12 % , e ) 40 %

A: e
****
Q: Problem: a chemical supply company has 60 liters of a 30 % hno 3 solution . how many liters of pure undiluted hno 3 must the chemists add so that the resultant solution is a 50 % solution ? 
Options: a ) 12 , b ) 15 , c ) 20 , d ) 24 , e ) 30

A:
d
****