Question

Suppose the clerk had to stack 200 boxes of cereal in a triagle. How many boxes would be on the bottom row?

Answer 1

If each row has 1 more box than the row above, a stack n rows high has n(n+1)/2 boxes in it.

n(n+1)/2 = 200
n^2 + n - 400 = 0
n 19.5

So, the first 19 rows would have 190 boxes. Don't know what he'll do with the other 10.