Hello

[crunkjosh]

Can you solve this?

A stack of oranges forms a pyramid with a rectangular base measuring 5 x 8 oranges. Each orange above level 1 rests in a pocket formed by 4 oranges on the level below it. A single row of oranges completes the stack. How many oranges are in the stack?

 

[stapel]

Work your way up. How many oranges are in the bottom layer? How wide and long will be the next layer? So how many oranges are in the next layer? And so forth, until you get to the layer that is only one orange wide. Add that layer's oranges, and you're done.

Eliz.

 

[soroban]

Hello, crunkjosh!

A stack of oranges forms a pyramid with a rectangular base measuring 5 x 8 oranges.
Each orange above level 1 rests in a pocket formed by 4 oranges on the level below it.
A single row of oranges completes the stack.
How many oranges are in the stack?

How hard can it be? . . . Draw a picture and count the oranges!

. . 5 x 8
oooooooo . . . . .4 x 7
oooooooo . . . ooooooo . . . . .3 x 6
oooooooo . . . ooooooo . . . .oooooo . . . . .2 x 5
oooooooo . . . ooooooo . . . .oooooo . . . . ooooo . . . . . 1 x 4
oooooooo . . . ooooooo . . . .oooooo . . . . ooooo . . . . . oooo
1st level . . . . 2nd level . . . 3rd level . . . 4th level . . . top level


If the bottom level were, say, 45 x 72 oranges, you might look for a formuila.