Hi Oliver,

You want all combinations from a set of six cities. Mathematicians usually call these subsets. So you want all subsets from a set of six cities. There is a response I gave to an earlier question but the original set only contains three items where you have six. Look at this response to see a way to approach this problem.

When you are done there is one further question to ask. One of the subsets you have created has no cities in it. Mathematicians call this the empty set. Do you want to include the empty set as one of your subsets?

Write back if you need more assistance,
Penny