SOLUTION: A display of blocks is arranged in a pyramid with five layers. The bottom layer has 36 blocks. The next layer has 25 blocks. The pattern continues so the top layer has 1 block.

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Question 604613: A display of blocks is arranged in a pyramid with five layers. The bottom layer has 36 blocks. The next layer has 25 blocks. The pattern continues so the top layer has 1 block. What is the total number of blocks in the display?

A 63
B 91
C 70
D 55

Answer by jim_thompson5910(28715) About Me  (Show Source):
You can put this solution on YOUR website!
You're adding the perfect squares of 36, 25, ... all the way down to 1. Recall that the perfect squares are

1, 4, 9, 16, 25, 36, ...

So just add up the first six perfect squares.