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: john found that the average of 15 numbers is 40 . if 12 is added to each number then the mean of number is ? 
Options: a ) 52 , b ) 45 , c ) 65 , d ) 78 , e ) 64
[EX A]: a

[EX Q]: Problem: how many halves are there in 9 - fourth ? 
Options: a ) 8 , b ) 4.5 , c ) 3.2 , d ) 7 , e ) 3
[EX A]: b

[EX Q]: Problem: a , b and c rents a pasture for rs . 870 . a put in 12 horses for 8 months , b 16 horses for 9 months and 18 horses for 6 months . how much should b pay ? 
Options: a ) 360 , b ) 227 , c ) 268 , d ) 198 , e ) 176
[EX A]:
a