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 product of two numbers is 2028 and their h . c . f is 13 . the number of such pairs is : 
Options: a ) 1 , b ) 2 , c ) 3 , d ) 4 , e ) 5
b

Problem: when positive integer x is divided by positive integer y , the remainder is 9 . if x / y = 96.12 , what is the value of y ? 
Options: a ) 96 , b ) 75 , c ) 48 , d ) 25 , e ) 12
b

Problem: the avg age of an adult class is 40 years . 12 new students with an avg age of 32 years join the class . therefore decreasingthe avg by 4 year . find what was the original strength of class ? 
Options: a ) 8 , b ) 12 , c ) 15 , d ) 16 , e ) 19

b