You have an empty 3-liter jug, an empty 5-liter jug, and an unlimited water supply. What is the minimum number of steps needed to end up with exactly 4 liters in the 5-liter jug? (A step is filling, emptying, or pouring between jugs).
6 steps
1) Fill 5L jug. 2) Pour 3L into 3L jug (2L left in 5L). 3) Empty 3L jug. 4) Pour 2L from 5L to 3L jug. 5) Fill 5L jug. 6) Pour 1L into 3L jug to top it off, leaving 4L in the 5L jug.
About this riddle
Math riddles hide a calculation inside a short story. Pull out the numbers, work out what is being asked, and watch for a trick such as a unit change.
Difficulty: Hard. More like this: Math riddles with answers or try Target 24 for a different kind of puzzle.
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