How many solutions in set N ∪ {0} have equation x1 + x2 + x3 = 100.

Results 1 to 3 of 3

- Jun 25th 2010, 01:16 PM #1

- Joined
- Jan 2010
- Posts
- 55

- Jun 25th 2010, 01:25 PM #2

- Joined
- May 2010
- Posts
- 1,034
- Thanks
- 28

lets fix a value of x1, say 5. How many solutions are left?

The new equation is x2+x3=100-5

Which has 96 solutions. These correspond to x2 taking every value between 0 and 95, and x3=95-x2.

Generalising, we could fix x1 at any value between 0 and 100.

So the number of solutions is:

Can you finish from there?

- Jun 25th 2010, 01:27 PM #3