



 
Hello,
For instance, I could pick the first donut, then replace it, then pick the first donut again, and replace it, then pick the 5th donut. If you wanted to know how many ways you could pick 3 donuts without replacement out of 6 you would get:
If you wanted to know how many ways you could pick 3 donuts without replacement out of 6, and where order doesn't matter (i.e. picking donuts 1, 2, and 3 is the same as picking donuts 2, 1, and 3) you would get: Division by the factorials removes “equivalent” choices. Tyler  


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