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: a = 4 ^ 15 - 625 ^ 3 and a / x is an integer , where x is a positive integer greater than 1 , such that it does not have a factor p such that 1 < p < x , then how many different values for x are possible ? 
Options: a ) none , b ) one , c ) two , d ) three , e ) four
[A]: c


[Q]: Problem: in a certain brick wall , each row of bricks above the bottom row contains one less brick than the row just below it . if there are 5 rows in all and a total of 50 bricks in the wall , how many bricks does the bottom row contain ? 
Options: a ) 12 , b ) 10 , c ) 9 , d ) 8 , e ) 11
[A]:
d