How many balls are there /b/?
>>688313882
enough to fill up ur mum
>>688313882
over 9000
>>688313882
atleast 7
>>688313882
9^2!
This is now a get thread.
Check em.
(sqrt(3)/4 * 9^2)+(sqrt(3)/4 * 8^2)+...
>>688313882
Not enough for op
>>688313882
285
>>688314076
81
/thread
Only 2 in my sac. But I know a guy with 3
>>688314247
Poor misled little thing, you can't /thread your own post.
165
Some decent balls in there, for their eras
204
>>688314441
165 pleb. it's fucking 284 you all suck summer fags
>>688314234
yep
>>688313882
163
285
>>688314507
Math?
For 165
9+8+7+6+5+4+3+2+1
8+7+6+5+4+3+2+1
7+6+5+4+3+2+1
Etc until you have your answer
>>688313882
420
165 OP
i don't care
>>688314568
How I got it:
9x9 + 8x8 + 7x7 + 6x6 + 5x5 + 4x4 + 3x3 + 2x2 + 1x1 = 285
>>688313882
>the inside of the tetrahedron is actually empty and all you fags got it wrong
the answer is always 42
>>688314772
Wrong
Base is a triangle not a square faggot
>>688314772
But it's a triangle
>>688314441
Winrar
>>688314234
This
>>688314896
No it's a squire, u imbosile.
>>688313882
There are 109 balls in that pyramid
1 on top
1×3 = 3
2×3 = 6
3×3 = 9
4×3 = 12
5×3 = 15
6×3 = 18
7×3 = 21
8×3 = 24
>>688315157
Except it's a square not a triangle.
>>688315216
NO ITS A SQUIRE U FUCKING IMBOSILE MY GOD HOW FUCKING OLD ARE YOU KID? PASS GRADE 3 BEFORE YOU FUCKING INSULT PEOPLES INTELLIGENSE YOU FUCKING KIDDO
Bunch of summerfags in here, the only answer is 165
>>688315292
RIP english
>>688313882
bout tree fiddy
the factorial method makes sense
>>688315373
FUCK YOU
>>688315216
The retardation is emanating off this post
>>688313882
284?
>>688315448
Ur d only retard here fag
1+(1+2)+(1+2+3)+(1+2+3+4)+(1+2+3+4+5)+(1+2+3+4+5)+(1+2+3+4+5+6)+(1+2+3+4+5+6+7)+(1+2+3+4+5+6+7+8)+(1+2+3+4+5+6+7+8+9)=165 faggots
>>688313882
165
>>688313882
If the height of the pyramid is N
The total number of balls is
SUM (from J=0 to J=N-1)
of
(J+1)*(N-J)
Since the height of this pyramid is 9 you get 165.
>>688314797
>tetrahedron
It's a fucking triangle
>>688314596
the only real answer
They teach this to 8 year olds.
Fuckwads. Its 285
>>688314437
Looks like he did. Just like I'm about to.
You faggot
/thread
>>688315676
tetrahedron means 4 sides.
a pyramid with a triangle base is a tetrahedron.
look up "4-sided dice"
>>688314797
>tetrahedron
look at this faggot
stupid summerfag
109 if its hollow
the sequence of growing triangles as you add on a new row is
1, 1+2, 1+2+3, 1+2+3+4, etc
so with the tetrahedron of 9 stacks, we have
9x1+8x2+7x3+6x4+5x5+4x6+3x7+2x8+1x9 =
165
>>688314772
Correct.
To lazy to count it out, but I'd assume you could start at the bottom,
>9+8+7+6+5+4+3+2+1
Next layer
>8+7+6+5+4+3+2+1
So on and so forth?