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'.

Problem: a man is 20 years older than his son . in two years , his age will be twice the age of his son . the present age of the son is ? 
Options: a ) 11 , b ) 25 , c ) 27 , d ) 18 , e ) 91
d

Problem: the tax on a commodity is diminished by 40 % but its consumption is increased by 25 % . find the decrease percent in the revenue derived from it ? 
Options: a ) 18 % , b ) 72 % , c ) 25 % , d ) 12 % , e ) 52 %
c

Problem: what is the remainder when 1250 * 1040 * 1057 * 1145 is divided by 32 ? 
Options: a ) 3 , b ) 5 , c ) 0 , d ) 2 , e ) 9

c