“I have two empty saucepans, one which can hold 3 pints; the other can hold 5 pints. How can I measure one pint of water without spilling any water on the ground?”
Pour 3 pints of water into your 3 pint saucepan. Then pour this water into your five pint saucepan. Now fill up your 3 pint saucepan again and then pour as much water as you can into your 5 pint saucepan. You will be left with exactly one pint.