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 Input:
Problem: the age of somu is one - third his father ' s . 10 years back he was one - fifth of his father ' s age . what is his persent age ?
Options: a ) 11 , b ) 13 , c ) 14 , d ) 12 , e ) 20

Ex Output:
e

Ex Input:
Problem: if t = 5 / 9 * ( k - 32 ) , and if t = 35 , then what is the value of k ?
Options: a ) 92 , b ) 95 , c ) 98 , d ) 101 , e ) 104

Ex Output:
b

Ex Input:
Problem: one pack of cake mix is being stirred before being poured into two separate baking trays . the first tray can hold a certain amount of cups of the mix while the other holds 20 cups less than the first . if the total number of cups poured is 500 , how many cups of batter does the second tray hold ?
Options: a ) 250 , b ) 260 , c ) 500 , d ) 280 , e ) 240

Ex Output:
e