Posted by **Carly** on Friday, September 14, 2012 at 1:38am.

You decide to build a pyramid out of wooden blocks. Each block must rest on the corners off 4 other blocks. If there is one block on top and 36 on the bottom, what is the total number of blocks you will need to complete the pyramid?

- Math -
**Reiny**, Friday, September 14, 2012 at 8:18am
The top layer has 1 block

the 2nd layer from the top has 4 blocks

the 3rd layer from the top has 9 blocks

the 4th has 16 blocks

the 5th has 25 blocks, and

the 6th has s36 blocks

So we have 1+4+9+16+25+36

= 91

btw, there is a formula for the sum of squares of the first n numbers

sumofsquares(n) = n(n+1)2n+1)/6

sumofsquares(6) = 6(7)(13)/6 = 91

## Answer This Question

## Related Questions

- Physics - Two blocks are stacked one on top of the other. The coefficient of ...
- physics - A block of mass 4.0 kg is put on top of a block of mass M = 6.0 kg. To...
- physics - A 4.0 kg block is put on top of a 5.0 kg block. To cause the top block...
- Pre-cal - Alicia wants to build a block pyramid similar to the one shown. block ...
- Physics - Two blocks, stacked one on top of the other, slide on a frictionless ...
- Physics - Two blocks, stacked one on top of the other, slide on a frictionless ...
- Math Physics - Two blocks of masses 40.0kg and 20.0kg are stacked on a table ...
- algebra2 - you are creating a window display at a toy store using wooden blocks...
- Math - Heather has a bag with 16 red blocks, 11 blue blocks, 9 purple blocks, ...
- Math - Heather has a bag with 16 red blocks, 11 blue blocks, 9 purple blocks, ...

More Related Questions