[Kodak]

We ecomodders like to fill our gas tanks consistently to full and generally avoid pumping extra gas to round to an exact dollar amount.

Now, most probably pay with credit cards and avoid change altogether. But I had this thought the other day:

Suppose you wanted to be prepared to give the cashier exact change, but of course you don't know what the exact cost will be. For this question, forget about paper dollars; we're only concerned about coins. What coin combination would you need to satisfy any change from 1 cent to 99 cents?

What is the fewest number of coins needed to satisfy this requirement, and what are those coins?

If I was more familiar with the Euro I would try to find the Euro equivalent for this question, but I don't know too much about the increments across the pond!