If you have 250 toothpicks, and want to make them into a pyramid (shown in photo), how many levels will it make?

I know there are 12 rows shown in the photo, but I'm not sure of the equation you need in order to actually find that there are 12 levels. Could anyone tell me? Thanks! :)

If you have 250 toothpicks and want to make them into a pyramid shown in photo how many levels will it make I know there are 12 rows shown in the photo but Im n class=

Respuesta :

Answer:

12 full levels

Step-by-step explanation:

There are multiple ways to do this, what I prefer is recursion

Let's define a equation which helps us determine the number of toothpicks of a pyramid with x levels f(x)

f(1)=3

f(2)=9

f(3)=18

f(4) =30

Etc Etc...

Eventually we can see that for every level x×3 toothpicks are added to f(x-1), so

f(x) = 3*x + f(x-1), so this becomes a geometric sequence 3*(1+2+3...+x)

Now we want to find out how many levels 250 toothpicks can make

250=3*(1+2+3+4..+x)

250/3 = 1+2+3...

I assume you want full levels so I will round down the answer, the closest you can get to 250/3 is (1+2+3...12)

So 12 full levels and a bit of extra toothpicks left