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: 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
a

Problem: at a restaurant , glasses are stored in two different - sized boxes . one box contains 12 glasses , and the other contains 16 glasses . if the average number of glasses per box is 15 , and there are 16 more of the larger boxes , what is the total number of glasses t at the restaurant ? ( assume that all boxes are filled to capacity . ) 
Options: a ) 96 , b ) 240 , c ) t = 256 , d ) t = 384 , e ) t = 480
e

Problem: if a = 105 and a ^ 3 = 21 * 49 * 45 * b , what is the value of b ? 
Options: a ) 25 , b ) 42 , c ) 45 , d ) 49 , e ) 54

a