Problem:
When four gallons are added to a tank that is one-third full, the tank is then one-half full. The capacity of the tank in gallons is
Answer Choices:
A.
B.
C.
D.
E.
Solution:
Since gallons is the difference between being full and full, it follows that gallons is of the capacity of the tank. Thus the capacity of the tank must be gallons.
Answer: .
The problems on this page are the property of the MAA's American Mathematics Competitions