Gold for 7 Days of Work

Question: You’ve got someone working for you for seven days and a gold bar to pay them. You must pay the worker for their work at the end of every day. If you are only allowed to make two breaks in the gold bar, how do you pay your worker? (Assuming equal amount of work is done during each day thus requiring equal amount of pay for each day)

Answer: The trick is not to try and how to cut in such a way to make 7 equal pieces but rather to make transactions with the worker. Make two cuts on the gold bar such that you have the following sizes of bars.

1/7, 2/7 and 4/7. For convenience sake, I would just refer to the bars as 1, 2 and 4.

At the end of Day 1: Give Bar 1 (You- 2 and 4, Worker- 1)

At the end of Day 2: Give Bar 2, Take back Bar 1 (You- 1 and 4, Worker- 2)

At the end of Day 3: Give Bar 1 (You- 4, Worker- 1 and 2)

At the end of Day 4: Give Bar 4, Take back Bar 1 and Bar 2 (You- 1 and 2, Worker- 4)

At the end of Day 5: Give Bar 1 (You- 2, Worker- 1 and 4)

At the end of Day 6: Give Bar 2, Take back Bar 1 (You- 1, Worker- 2 and 4)

At the end of Day 7: Give Bar 1 (You- Empty, Worker- 1, 2 and 4)

That should take care of everything.

If you have any questions, please feel free to send me an email at support@mytechinterviews.com. If you have any interview questions which you feel would benefit others, I would love to hear about it.

8 Comments

8 Responses

  1. Yash says:

    Initially break the 7segment block in to following segments
    i(blocksegment)
    ii(blocksegment)
    iiii(blocksegment)
    1day-> Give i(blocksegment)
    2day -> Give ii(blocksegment) &
    take back i(blocksegment)
    3day -> Give i(blocksegment)
    4day -> Give iiii(blocksegment) & take back i , ii blocksegments
    5 day -> Give i(blocksegment)
    6day -> Give ii(blocksegment) &
    take back i(blocksegment)
    7day -> Give i(blocksegment)

  2. Tal Achituv says:

    When you’re asked this during an interview, your thought process should be:

    1) I need to cut the bar into 7 equal pieces with only two cuts. This is clearly impossible.

    2) Lets re-state the problem:
    The worker needs to have 1/7 of a bar at the end of day 1 and 2/7 of a bar at the end of day 2, and so on…

    While the original ‘assumed’ requirement was clearly impossible to satisfy, this re-stated one is not impossible or at least it is not as clear that it is impossible…

    You should try to figure out a way of solving it or proving that it as well is impossible.

    Hopefully while trying to do that you’ll think of the option of “transactions”.

  3. Ace says:

    what if I spent the gold by the end of the next day?

  4. Candy says:

    @Doc – sorry, if you go to the shop, have to pay 3 $ but only have a 10$ bill, don’t you give them the 10$ bill and expect 7$ back !??!

    The solution is correct

  5. sailee says:

    dis is d same answer i thought for dis puzzle …
    i m convinced.

  6. IQ250 says:

    ” You must pay the worker for their work at the end of every day……….”

    First we are giving them more than their wages and then after realiZin takin thm bak……

    wat d hell is dis??

  7. Doggie says:

    Isn’t like asking for change?

    You: Do you have change for 2/7 of a gold bar?
    Worker: Of course I do, here you go :)

  8. Doc says:

    Who would answer it this way? I don’t see why anyone would think about taking money back from someone you pay? You can’t count on the money being there on day 2, 3, etc. People have a habit of spending money.

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