Problem:
Which of the following is equal to
21−3131−41?
Answer Choices:
A. 41
B. 31
C. 21
D. 32
E. 43
Solution:
The least common multiple of 2,3, and 4 is 12 , and
21−3131−41⋅1212=6−44−3=(C)21
The problems on this page are the property of the MAA's American Mathematics Competitions