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: marcella has 27 pairs of shoes . if she loses 9 individual shoes , what is the greatest number of matching pairs she could have left ? 
Options: a ) 22 , b ) 20 , c ) 19 , d ) 16 , e ) 15

SOLUTION: a

PROBLEM: Problem: ( 18 ) 7 x ( 5832 ) - 2 ÷ ( 324 ) - 1 = ( 18 ) 7 
Options: a ) 5 , b ) 4 , c ) 3 , d ) 2 , e ) 1

SOLUTION: c

PROBLEM: Problem: if x is equal to the sum of the integers from 20 to 40 , inclusive , and y is the number of even integers from 20 to 40 , inclusive , what is the value of x + y ? 
Options: a ) 601 , b ) 611 , c ) 621 , d ) 631 , e ) 641

SOLUTION:
e