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: in a theater , the first row has 12 seats and each row has 2 more seats than previous row . if the last row has 48 seats , what is the total number of seats in the theater ? 
Options: a ) 550 , b ) 570 , c ) 590 , d ) 610 , e ) 630
[EX A]: b

[EX Q]: Problem: how many integerskgreater than 100 and less than 1100 are there such that if the hundreds and the units digits ofkare reversed , the resulting integer is k + 99 ? 
Options: a ) 50 , b ) 60 , c ) 70 , d ) 80 , e ) 90
[EX A]: e

[EX Q]: Problem: at the end of year x , automobile installment credit accounted for 35 % of all outstanding consumer installment credit . at that time automobile finance companies extended $ 40 billion of credit , or 1 / 3 of the automobile installment credit . how many billion dollars of consumer installment credit was outstanding at that time ? 
Options: a ) 120 , b ) 300 , c ) 401.36 , d ) 350.15 , e ) 342.86
[EX A]:
e