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 x is a randomly chosen integer between 1 and 20 , inclusive , and y is a randomly chosen integer between 21 and 40 , inclusive , what is the probability that xy is a multiple of 4 ? 
Options: a ) 1 / 4 , b ) 1 / 3 , c ) 3 / 8 , d ) 7 / 16 , e ) ½
[EX A]: e

[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

[EX Q]: Problem: a student chose a number , multiplied it by 4 , then subtracted 138 from the result and got 102 . what was the number he chose ? 
Options: a ) 60 , b ) 120 , c ) 130 , d ) 140 , e ) 150
[EX A]:
a