You are in a bathroom with stone walls and no windows. You start to run a bath when the handles come off and there is no way of turning the tap off. You can't escape because the door is locked and there are no windows. The room will flood and you will drown. How can you save yourself?
Pull the plug in the tub.
You have a 4 gallon and a 7 gallon jug of water. How can you measure exactly 6 gallons of water using these two jugs?