Originally posted by skims How is 0! equal to 1? Can someone please explain it to me?

Thanks

It's to make the following equation work. (x!)/(y!)=(x-y)! This works for all numbers. I'll give an example, let's say x,y=3, then it would be (3!)/(3!)=(3-3)! ---> 6/6=0! 1=1 and the equation holds since 0!=1. But if it equalled zero, like you'd expect, then the equation wouldn't work.

Originally posted by nickhawker That sounds like a botch job to me. What is the factorial of a negative number?

Actually, my equation doesn't work. It must be some different one. I do know that the factorial of 0 is 1 though. I'll let someone with more experience (and memory ðŸ˜›) take over for me in explaining this.

This is not the first time this subject has been visited in this forum... there was a thread called 0! in this forum posted on Jun 20, 2004. Right now, it's on page 20 of this forum if you care to take a look...

Originally posted by Suzianne This is not the first time this subject has been visited in this forum... there was a thread called 0! in this forum posted on Jun 20, 2004. Right now, it's on page 20 of this forum if you care to take a look...