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 weight of a , b , c is 45 kg . the avgwgt of a & b be 40 kg & that of b , c be 43 kg . find the wgt of b . 
Options: a ) 23 , b ) 43 , c ) 21 , d ) 31 , e ) 43

A: d
****
Q: Problem: harold works at a resort from the beginning of march to the end of september . during the month of august this past year , he made 4 times the average ( arithmetic mean ) of his monthly totals in tips for the other months . his total tips for august were what fraction of his total tips for all of the months he worked ? 
Options: a ) 1 / 3 , b ) 2 / 5 , c ) 3 / 7 , d ) 1 / 2 , e ) 4 / 7

A: b
****
Q: Problem: if 5 < x < 8 < y < 13 , then what is the greatest possible positive integer difference of x and y ? 
Options: a ) 3 , b ) 4 , c ) 5 , d ) 6 , e ) 7

A:
e
****