A man went down to the river with two jugs, one of three-liter
capacity and one of five-liter capacity. Using just these ,
how did he bring back exactly four liters?
1. Fill 5L jug,
2. Fill 3L jug with the water from the 5L jug,
3. Empty 3L jug and Pore the remaining 2L from the 5L jug in
the 3L jug
4. Fill 5L jug, fill 3L jug (that has 2L in it) with the the
filled 5L jug.
5. now you have 4L in the 5L jug.