



 
Hi Mark. Think about it this way. You have ten different balls each with a digit For the first position A, you have ten balls to draw from, so there are Now for the next position B, you have one less ball, so there are 9 choices. If there were 10 choices for the first ball and 9 choices for the Now continue this pattern. How many choices for the next ball and so These are what we call "permutations". That's when order matters. When Cheers,  


Math Central is supported by the University of Regina and The Pacific Institute for the Mathematical Sciences. 