A man's car runs out of gasoline. His car tank holds exactly 13 gallons. He has three empty unmarked containers which can hold 3 gallons, 6 gallons, and 11 gallons. Using only these containers at the gas station, how can the man bring back exactly 13 gallons?

(He is not allowed to buy over 13 gallons and dispose of the extra.)

this is honestly a stretch..but i see no other way in doing this without "eyeballing" or using the gas meter.for the sake of this..GC = Galloncontainer, or w/e..

fill the 3, dump in 6. (+3 in 6GalCon.)
fill 3 again. (+3 in 3 GalCon.)
put both smaller containers in 11, the smallest one on the bottom..(+0 in 11GC, +3 in 3GC, +3 in 6GC)..
you now only have enough room in 11GC for 2 gallons, so fill it.(+2 in 11GC)
take out the 6 gallon one (which should be floating due to air inside container), and dump the 2 gallons from 11 into 6. (so 5gal in 6GC, 0gal in 11gGC, and 3 in 3GC).
FINALLY...put he 6 gallon back into the 11GC and fill up the 11GC.

THEREFORE...you will have 2 gallons in 11gc, 5 gallons in the 6GC, and 3 in the 3GC...adding...2+5+6...gives us 13gallons. =)

unlucky number..but it's done.

Posted by Amon on 2005-05-11 22:22:21