At the grocery store, I bought 4 different items. I brought 4 identical bags, and handed them to the cashier. How many ways are there for the cashier to put the items I bought in the 4 identical bags, assuming he might leave some of the bags empty?
4 + 4! + 4!/4 + 1 =4 + 24 + 6 + 1 = 35 ways
