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: of the final grades received by the students in a certain math course , 1 / 5 are a ' s , 1 / 4 are b ' s , 1 / 2 are c ' s , and the remaining 30 grades are d ' s . what is the number of students in the course ? 
Options: a ) 80 , b ) 110 , c ) 160 , d ) 600 , e ) 400

SOLUTION: d

PROBLEM: Problem: 49 ã — 49 ã — 49 ã — 49 x 49 = 7 ? 
Options: a ) 4 , b ) 7 , c ) 8 , d ) 10 , e ) none of these

SOLUTION: d

PROBLEM: Problem: what is the units digit of 33 ^ 2 * 17 ^ 3 * 39 ^ 2 ? 
Options: a ) 1 , b ) 3 , c ) 5 , d ) 7 , e ) 9

SOLUTION:
d