A local grocer delivers lemonade using two full 10 pint jugs.
Recently, the grocer delivered to a pair of customers who had a five pint jug and a four pint jug between them.
Each wanted two pints of lemonade though.
How did the grocer measure two pints into each jug only using the two 10 pint jugs and the customers' jugs?
The jugs are not marked in any way and there was no other container which could be used.