Problem:
A grocer makes a display of cans in which the top row has one can and each lower row has two more cans than the row above it. If the display contains cans, how many rows does it contain?
Answer Choices:
A.
B.
C.
D.
E.
Solution:
If there are rows in the display, the bottom row contains cans. The total number of cans is therefore the sum of the arithmetic series
which is
Thus , so .
Answer: .
The problems on this page are the property of the MAA's American Mathematics Competitions