Using application-based problems, develop formulas for permutations, combinations, and combinations with repetition and compare student-derived formulas to standard representations of the formulas.
Example: If there are r objects chosen from n objects, then the number of permutations can be found by the product $[n(n-1) … (n-r)(n-r+1)]$ as compared to the standard formula $n!/(n-r)!$.
