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 Q]: Problem: a company has 15 managers and 75 associates . the 15 managers have an average salary of $ 90,000 . the 75 associates have an average salary of $ 30,000 . what is the average salary for the company ? 
Options: a ) $ 35,000 , b ) $ 40,000 , c ) $ 55,000 , d ) $ 65,000 , e ) $ 75,000
[EX A]: b

[EX Q]: Problem: caleb spends $ 64.50 on 50 hamburgers for the marching band . if single burgers cost $ 1.00 each and double burgers cost $ 1.50 each , how many double burgers did he buy ? 
Options: a ) 29 , b ) 10 , c ) 20 , d ) 40 , e ) 45
[EX A]: a

[EX Q]: Problem: the average age of 35 students in a class is 16 years . the average age of 21 students is 14 . what is the average age of remaining 7 students ? 
Options: a ) 14 years , b ) 17 years , c ) 19 years , d ) 38 years , e ) none
[EX A]:
d