You have an empty 7-liter bucket, an empty 4-liter bucket, and an unlimited supply of water. Neither bucket has any measurement markings. How can you measure out exactly 5 liters of water into the 7-liter bucket?
Fill the 4L bucket, pour it into the 7L bucket, fill the 4L bucket again, fill the 7L bucket to capacity (leaving 1L in the 4L bucket), empty the 7L bucket, transfer the 1L into the 7L bucket, and finally pour a full 4L bucket into the 7L bucket
Step 1: Fill 4L bucket, pour into 7L (7L has 4L). Step 2: Fill 4L bucket, pour into 7L until full (7L has 7L, 4L has 1L remaining). Step 3: Empty 7L bucket, pour the 1L from 4L into 7L (7L has 1L). Step 4: Fill 4L bucket completely and pour into 7L bucket. 1L + 4L = 5L in the 7L bucket.
About this riddle
Logic riddles give you a few facts and ask what must be true. List what you know, cross out what cannot be, and see what is left.
Difficulty: Medium. More like this: Logic riddles with answers or try Einstein's Logic Grid for a different kind of puzzle.
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