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: if a * b * c = ( √ ( a + 2 ) ( b + 3 ) ) / ( c + 1 ) , find the value of 6 * 15 * 3 . 
Options: a ) 8 , b ) 5 , c ) 11 , d ) 3 , e ) 4
[EX A]: d

[EX Q]: Problem: when toys are grouped into 12 and 18 , always 3 toys remain ungrouped . what is the minimum number of toys to be added so that when they are grouped into 7 , no toys will remain ungrouped ? 
Options: a ) 0 , b ) 1 , c ) 2 , d ) 3 , e ) 4
[EX A]: d

[EX Q]: Problem: the tax on a commodity is diminished by 32 % but its consumption is increased by 12 % . find the decrease percent in the revenue derived from it ? 
Options: a ) 20 % , b ) 18 % , c ) 15 % , d ) 12 % , e ) 24 %
[EX A]:
e