This is great use case.
Let me know what you have tried?
Anyway it should be something simple as :
1.Create the rule and put the details/filters as appropritate.
2. Within the "AND":
-Specify "time window"
-Leave the "sequence" check box unticked.
That should be pretty much enough, but the best will be to test with some more generic events so you could ensure it's behaving as expected.
There are other ways to do it but they will be much more complicated.