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: 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
e

Problem: the average of 6 quantities is 8 . the average of 4 of them is 5 . what is the avg . of the remaining 2 numbers ? 
Options: a ) 11 , b ) 12 , c ) 13 , d ) 14 , e ) 15
d

Problem: in a company of 15 employees , 6 employees earn $ 37,000 , 5 employees earn $ 42,000 , and the 4 highest - paid employees earn the same amount . if the average annual salary for the 15 employees is $ 45,000 , what is the annual salary for each of the highest - paid employees ? 
Options: a ) $ 56,250 , b ) $ 57,750 , c ) $ 59,250 , d ) $ 60,750 , e ) $ 62,250

d