Problem:
Mr. Harman needs to know the combined weight in pounds of three boxes he wants to mail. However, the only available scale is not accurate for weights less than pounds or more than pounds. So the boxes are weighed in pairs in every possible way. The results are and pounds. What is the combined weight in pounds of the three boxes?
Answer Choices:
A.
B.
C.
D.
E.
Solution:
Because each box is weighed two times, once with each of the other two boxes, the total pounds is twice the combined weight of the three boxes. The combined weight is pounds.
Answer: .
The problems on this page are the property of the MAA's American Mathematics Competitions