A man runs his car out of gas thereby completely emptying his 16 gallon tank. He only has a 3, a 6, and a 11 gallon container (and fortunately a wagon to carry the containers in) in his trunk. He has nothing else in which he can carry gas. He walks a few miles to a gas station, and as luck would have it the gauge on the pump is broken so he can not use that to measure the fuel. He is in a pretty remote area with only one gas station for miles. Gas costs $3.09⁹, and he only has a $50. Using only the containers provided, and only walking once to and from the gas station, how can he get exactly 16 gallons of gas into his car?

i came across this site last night and i liked the out of gas puzzle. it kept me awake for a long time until i came up with this solution:

fill the 11 gallon container with water.

fill the 3 gallon container from the 11 gallon container.

mark the water level on the 11 gallon container (8 gallons)

empty thoroughly both containers.

fill the 11 gallon container exactly to the mark (8 Gallons)

Pour the 8 gallons into the 6 gallon and 3 gallon containers

refill the 11 gallon container up to the mark (8 gallons)

Pay for 16 gallons and away he goes

Posted by tom reapy on 2008-04-20 18:10:10