When making sets that do not include all the numbers that are possible (eg how many set of five can be made from eight dogs, or how many seven person sets can be made with nine people) when do you use nPr and when do you use nCr?
Permutation: A set of objects in which position (or order) is important=nPr=68P5=1,250,895,360 Combination: A set of objects in which position (or order) is NOT important.=nCr=68C5=10,424,128