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: gold is 19 times as heavy as water and copper is 9 times as heavy as water . in what ratio should these be mixed to get an alloy 15 times as heavy as water ? 
Options: a ) 3 : 2 , b ) 3 : 8 , c ) 5 : 7 , d ) 3 : 7 , e ) 3 : 6
[EX A]: a

[EX Q]: Problem: what is the greatest integer m for which the number 30 ! / 10 ^ m is an integer ? 
Options: a ) 7 , b ) 8 , c ) 9 , d ) 10 , e ) 11
[EX A]: a

[EX Q]: Problem: louie takes out a 3 - month loan of $ 1000 . the lender charges him 10 % interest per month compounded monthly . the terms of the loan state that louie must repay the loan in 3 equal monthly payments . to the nearest dollar , how much does louis have to pay each month ? 
Options: a ) 333 , b ) 383 , c ) 402 , d ) 433 , e ) 483
[EX A]:
c