How do I get 4 gallons with a 5 gallon and 7 gallon bucket?

Answer by  Mac44 (479)

Fill the 7 gallon bucket, dump it into the 5 gallon bucket. Empty the 5 gallon bucket and dump the remaining two gallons from the 7 gallon bucket into the 5 gallon bucket. Fill the 7 gallon bucket again, fill the 5 gallon bucket from the 7 gallon bucket. After filling those 3 gallons, there will be 4 gallons left.

Answer by  esteban (1334)

Fill the 7 gallon bucket. Then empty it into the 5 gallon bucket. This will leave 2 gallons in the bucket. Pour this into a third bucket, then repeat.