TASK DEFINITION: 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: 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

SOLUTION: d

PROBLEM: Problem: if x + ( 1 / x ) = 5 , what is the value of w = x ^ 2 + ( 1 / x ) ^ 2 ? 
Options: a ) w = 21 , b ) w = 22 , c ) w = 23 , d ) w = 24 , e ) 27

SOLUTION: c

PROBLEM: Problem: if the price of a book is first decreased by 20 % and then increased by 20 % , then the net change in the price will be : 
Options: a ) 10 , b ) 388 , c ) 4 , d ) 29 , e ) 22

SOLUTION:
c