OP solved it, closing

You wish was granted some time ago

That's not a suggestion.

This is highly inefficient -> O(n^2) if the 2 arrays are of equal length. Improve it.

Not an issue

This is a bug. Clearly with peopleInLine = [25,25,25,25,25,100]; you have enough cash and bills for all so you should expect a YES.

This kata is broken.

Why would the following : 25,25,25,25,25,100 expect a NO? I have dictionary for the "cash register" and I have enough "bills" to cover a 75$ cash return for the person in line when I come at he 100. Can someone explain this one to me ?

One of the test values is zero, gives an ArgumentOutOfRangeException which is expected

What language are you using here?

I already have tests for different currencies.

All my code is working. Although, it's too slow (took more than 6s)
What can I do to speed my code while using static methods/class