Question

ARITHMETIC SERIES:
A child is creating a pyramid with building blocks. The top three levels include 5 blocks, 12 blocks, and 19 blocks.

Part 1: How many blocks would be needed for a pyramid 25 levels tall?

Part 2: Use complete sentences to explain how a sum of an arithmetic series was applied.

I have this: Sn= 25/2 * 2(5)+(25-1)7
25/2 * 1680 ????

Answer 1

* 25/2

Answer 2

Should be n/2 = 25/2, not 25/5.

Answer 3

Yeah I corrected myself after

Answer 4

I'm just not sure if that's the answer I'm suppose to get

Answer 5

Well, your work above says 25/5 so I don't know what your corrected work now says.

Answer 6

I can only work with what you showed me above and that answer above is wrong.

Answer 7

there it's edited

Answer 8

25/2 *( 2(5)+(25-1)7)
Just use that.

Answer 9

I did. I got 25/2 * 1680 but that's not a real answer and I've seen other post saying it's 25550.

Answer 10

Hold on.

Answer 11

I got 2225.

Answer 12

how????

Answer 13

i keep gettting 2100

Answer 14

*21000