# Number of Tennis Balls to make a 4 sided pyramid of 25 levels

# Answer : 5525 Balls

Start from the top of the pyramid.
For a pyramid of 1 level - Number of Tennis balls required is 1
For a pyramid of 2 level - Number of Tennis balls required is 1 + 4
For a pyramid of 3 level - Number of Tennis balls required is 1 + 4 + 9
For a pyramid of 4 level - Number of Tennis balls required is 1 + 4 + 9 + 16
How do you go about doing this is each level of N balls requires N+1 balls as support in the case of 2 dimensional pyramid, since this has 3 dimensions, each N^{2} ball requires support from (N+1)^{2} ,
therefore there would be N^{2} Balls in N^{th} level where N is 1,2,3,4... 25. So the answer here is
1^{2} + 2^{2} + 3^{2} + 4^{2} + 5^{2} + .... + 25^{2}
Using this formula to calculate the sum of squares of first N integers , we can calculate the number of balls requires as
## (25 x (26) x (51) ) / 6 = 5525

10 Dec, 2009

Comments (0)

You may also like

Recent Comments

- Siri and Uber also uses Location Services
2 years, 10 months ago

- i connected my dell laptop to videocon lcd ...
2 years, 11 months ago

- 05/03/2014_22:09:18,97 C:\Users\kampar>touch .htaccess 'touch' is not recognized as ...
3 years, 1 month ago

- IRCTC Tatkal ticket booking script required...
3 years, 2 months ago

- I have a similar solution. I was told ...
3 years, 10 months ago

- Can you try checking with a different cable ...
4 years, 1 month ago

- wow that's hilarious
4 years, 1 month ago

- Perfect! Thanks! :D
4 years, 1 month ago

- Having the same issue. Were you able to ...
4 years, 1 month ago

- hi im having problem with the hdmi port.. ...
4 years, 1 month ago

- Hi, As of today the way2sms website has ...
4 years, 2 months ago

- HI! I have a problem with my lg ...
4 years, 5 months ago

- You know what would be a GREAT idea ...
4 years, 5 months ago

- Hi, For changing MAC address in win7 just ...
4 years, 6 months ago

- anybody who might read this now should be ...
4 years, 6 months ago