In this task, you need to provide the correct option for a given problem from the provided options.

[Q]: Problem: the duplicate ratio of 6 : 4 is ? 
Options: a ) 1 : 2 , b ) 9 : 4 , c ) 1 : 8 , d ) 1 : 18 , e ) 1 : 13
[A]: b


[Q]: Problem: two whole numbers whose sum is 36 can not be in the ratio 
Options: a ) 2 : 4 , b ) 3 : 4 , c ) 3 : 6 , d ) 1 : 3 , e ) 3 : 36
[A]: b


[Q]: Problem: if 70 percent of a class answered the first question on a certain test correctly , 55 percent answered the second question on the test correctly , and 20 percent answered neither of the questions correctly , what percent answered both correctly ? 
Options: a ) 45 % , b ) 40 % , c ) 35 % , d ) 30 % , e ) 25 %
[A]:
a