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'.

Problem: what is the average of first 21 multiples of 6 ? 
Options: a ) a ) 66 , b ) b ) 77 , c ) c ) 79 , d ) d ) 81 , e ) e ) 82
a

Problem: a father said his son , ` ` i was as old as you are at present at the time of your birth . ` ` if the father age is 32 now , the son age 5 years back was 
Options: a ) 11 , b ) 17 , c ) 11 , d ) 19 , e ) 99
a

Problem: the average of 10 numbers is 7 . if each number is multiplied by 12 , then the average of new set of numbers is 
Options: a ) 28 , b ) 236 , c ) 288 , d ) 84 , e ) 26

d