Problem:
Rohan keeps a total of guppies in fish tanks.
How many guppies are in the tank?
Answer Choices:
A.
B.
C.
D.
E.
Solution:
Let be the number of guppies in the st tank. Hence, there are guppies in the nd tank, guppies in the rd tank, and guppies in the th tank. We then use the fact that there are a total of guppies in the tanks to find :
This simplifies to . Solving for gives: .
Note that we are not yet done since we are asked for the number of guppies in the th tank and not the st. There are guppies in the th tank.
Thus, is the correct answer.
Answer: .
The problems on this page are the property of the MAA's American Mathematics Competitions