In this task, you need to answer the given multiple-choice question on the general math. Classify your answers into 'a', 'b', 'c', 'd', and 'e'.

[EX Q]: Problem: if n is a natural number , then ( 6 n ^ 2 + 6 n ) is always divisible by 
Options: a ) 6 only , b ) 6 and 12 both , c ) 12 only , d ) 18 only , e ) 12 and 18 both
[EX A]: b

[EX Q]: Problem: if a ' s salary is 20 % less than b ' s salary , by how much percent is b ' s salary more than a ' s ? 
Options: a ) 5 % , b ) 10 % , c ) 15 % , d ) 25 % , e ) none
[EX A]: d

[EX Q]: Problem: in smithtown , the ratio of right - handed people to left - handed people is 3 to 1 and the ratio of men to women is 3 to 2 . if the number of right - handed men is maximized , then what percent z of all the people in smithtown are left - handed women ? 
Options: a ) 50 % , b ) 40 % , c ) 25 % , d ) 20 % , e ) 10 %
[EX A]:
c