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'.

Problem: a company produces on an average 4000 items per month for the first 3 months . how many items it must produce on an average per month over the next 9 months , to average of 4375 items per month over the whole ? 
Options: a ) 4500 , b ) 4600 , c ) 4680 , d ) 4710 , e ) none
a

Problem: a is the hundreds digit of the 3 digit integer x , b is the tens digit of x , and c is the units digit of x . 4 a = 2 b = c , and a > 0 . what is the difference between the two greatest possible values of x ? tip : dont stop till you have exhausted all answer choices to arrive at the correct one . 
Options: a ) 124 , b ) 297 , c ) 394 , d ) 421 , e ) 842
a

Problem: find the sum of first 32 natural numbers 
Options: a ) 470 , b ) 468 , c ) 465 , d ) 463 , e ) 528

e