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: 19.19 / 2000 is equal to : 
Options: a ) 1.01252633 , b ) 0.01262533 , c ) 0.12526333 , d ) 0.012793333 , e ) 0.12725333
[EX A]: d

[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: the sum of all the integers k such that – 21 < k < 24 is 
Options: a ) 0 , b ) - 2 , c ) - 25 , d ) - 39 , e ) - 51
[EX A]:
d