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: gold is 10 times as heavy as water and copper is 6 times as heavy as water . in what ratio should these be mixed to get an alloy 8 times as heavy as water ? 
Options: a ) 3 : 2 , b ) 1 : 1 , c ) 3 : 1 , d ) 5 : 2 , e ) 4 : 3
[A]: b


[Q]: Problem: ( 0.15 ) ( power 3 ) - ( 0.1 ) ( power 3 ) / ( 0.15 ) ( power 2 ) + 0.015 + ( 0.1 ) ( power 2 ) is : 
Options: a ) 0.68 , b ) 0.08 , c ) 0.05 , d ) 0.06 , e ) none of them
[A]: c


[Q]: Problem: when 1 / 20 % of 4,000 is subtracted from 1 / 10 of 4,000 , the difference is 
Options: a ) 50 , b ) 200 , c ) 380 , d ) 398 , e ) 400
[A]:
d