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: what is the minimum percentage increase in the mean of set f { - 4 , - 1 , 0 , 6 , 9 } if its two smallest elements are replaced with two different primes ? 
Options: a ) 25 % , b ) 50 % , c ) 75 % , d ) 100 % , e ) 200 %

SOLUTION: d

PROBLEM: Problem: if - 3 x + 2 y = 28 and 3 x + 6 y = 84 , what is the product of x and y ? 
Options: a ) 264 . , b ) 428 , c ) 0 , d ) 462 , e ) 642

SOLUTION: c

PROBLEM: Problem: 22.085 ã — 0.001 = ? 
Options: a ) 0.22085 , b ) 2.2085 , c ) 0.022085 , d ) 0.0022085 , e ) none of these

SOLUTION:
c