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'.

[Q]: Problem: the average marks of a class of 40 students is 44 and that of another class of 45 students is 70 . find the average marks of all the students ? 
Options: a ) 52.6 , b ) 52.4 , c ) 52.1 , d ) 69.5 , e ) 52.9
[A]: d


[Q]: Problem: cost is expressed by the formula tb ^ 4 . if b is doubled , the new cost is what percent of the original cost ? 
Options: a ) 200 , b ) 600 , c ) 800 , d ) 1600 , e ) 50
[A]: d


[Q]: Problem: 52 is to be divided into two parts such that the sum of 10 times the first and 22 times the second is 780 . the bigger part is : 
Options: a ) 30.33 , b ) 34.44 , c ) 26.1 , d ) 28.0 , e ) 21.0
[A]:
a