Problem:
Brent has goldfish that quadruple (become four times as many) every month, and Gretel has goldfish that double every month. If Brent has goldfish at the same time that Gretel has goldfish, then in how many months from that time will they have the same number of goldfish?
Answer Choices:
A.
B.
C.
D.
E.
Solution:
Make a table.
Thus it takes months for the number of goldfish to be equal.
The ratio of the number of Gretel's goldfish to the number of Brent's goldfish decreases by a factor of every month. Because they initially differ by a factor of , this indicates that the process will take months.
Answer: .
The problems on this page are the property of the MAA's American Mathematics Competitions