In this section we reviewed the Inclusion Exclusion general formula and solved the problem of seating 10 couples around a table such that no couple sits next to his or her partner. Then we explained the multinomial coefficients which led us to the Multinomial Theorem. Finally we looked at combinations of distinguishable and indistinguishable balls in urns allowing firstly for the case that all urns are non empty and then extending this to allow empty urns.