Goldman Sachs Interview Question: brain teaser - a 3 gallon buc... | Glassdoor

Interview Question

Summer Analyst Interview New York, NY

brain teaser - a 3 gallon bucket and a 5 gallon bucket. How

  do you get 4 gallons?

Interview Answer

5 Answers


Fill the 5G jug and pour it into the three gallon jug. Discard 3 gallon jug. Pour the 2 gallons from the 5 gallon jug into the 3 gallon jug. Fill 5 gallon jug again and pour one gallon into the 3 gallon jug. 3+1=4

Anonymous on Oct 7, 2012

Fill the 5G jug and pour into the 3G. Discard the contents of the 3G jug and pour the 2G into the empty 3G. Make a mark on the 3G to know where the 2G level is. Pour the 2G into the now empty 5G, fill the 3G to the mark you made and pour it into the 5G jug.

ManicPanic on Oct 18, 2012


Fill 5G, pour into 3G. Dump 3G. Dump remaining 2g into 3G. (now you have 2g in 3G)
Fill 5G. Pour into 3G until full (+1g).
The remaining amount in your 5G is exactly 4g.

Anonymous on Nov 9, 2012

I think the simplest way is to pour the 3 gallon into the 5 gallon twice so youll end up with one gallon left in the 3 gallon. pour that into the 5, and fill up 3G again and pour that into five..

YV3 on Nov 28, 2012

fill 5 gallon with 2 times 3 gallon. The second time 3 gallon would have 1 gallon remaining in it . now put it in outside box.take 5 gallon content and put it back in 3 gallon.
already 1 gallon in outside+3 gallon here = 4 gallon

SriramMS on Mar 15, 2013

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