4.5.2 Applications of Inclusion-Exclusion principle The number of r-combinations of multiset s 1. The number of r-combinations of multiset s If r<n, and there is in general, no simple formula for the number of r-combinations of S. Nonetheless a solution can be obtained b the inclusion-exclusion principle 4.5▪ 4.5.2 Applications of Inclusion-Exclusion principle ▪ The number of r-combinations of multiset S ▪ 1. The number of r-combinations of multiset S ▪ If r<n, and there is, in general, no simple formula for the number of r-combinations of S. Nonetheless a solution can be obtained by the inclusion-exclusion principle 4.5