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'.

Example Input: Problem: mary ' s income is 60 % more than tim ' s income and tim ' s income is 10 % less than juan ' s income . what % of juan ' s income is mary ' s income . 
Options: a ) 144 % , b ) b . 120 % , c ) 96 % , d ) 80 % , e ) 64 %
Example Output: a

Example Input: Problem: the sum of ages of 5 children born at the intervals of 3 years each is 80 years . what is the age of the youngest child ? 
Options: a ) 3 years , b ) 4 years , c ) 6 years , d ) 7 years , e ) 10 years
Example Output: e

Example Input: Problem: if 2994 ã · 14.5 = 177 , then 29.94 ã · 1.45 = ? 
Options: a ) 17.1 , b ) 17.3 , c ) 17.5 , d ) 17.7 , e ) 17.2
Example Output:
d