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: 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
[EX A]: d

[EX Q]: Problem: if 7 ^ k = 2 , then 7 ^ ( 4 k + 2 ) = 
Options: a ) 729 , b ) 754 , c ) 784 , d ) 783 , e ) 108
[EX A]: c

[EX Q]: Problem: of the goose eggs laid at a certain pond , 2 / 3 hatched and 3 / 4 of the geese that hatched from those eggs survived the first month . of the geese that survived the first month , 3 / 5 did not survive the first year . if 130 geese survived the first year and if no more than one goose hatched from each egg , how many goose eggs were laid at the pond ? 
Options: a ) 280 , b ) 400 , c ) 540 , d ) 650 , e ) 840
[EX A]:
d