Problem:
(6 ? 3)+4−(2−1)=5. To make this statement true, the question mark between the 6 and the 3 should be replaced by
Answer Choices:
A. ÷
B. ×
C. +
D. −
E. None of these
Solution:
(6?3)+4−(2−1)=5(6?3)+4−1=5(6?3)+3=5(6?3)=2(6÷3)=2(subtract: 2−1=1)(subtract: 4−1=3)(subtract 3 from both sides)
The other operations produce the following result:
(6+3)+4−(2−1)=9+4−1=12(6−3)+4−(2−1)=3+4−1=6(6×3)+4−(2−1)=18+4−1=21
Answer: A.
The problems on this page are the property of the MAA's American Mathematics Competitions