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 email@example.com. If you have any interview questions which you feel would benefit others, I would love to hear about it.If you're looking for some serious preparation for your interviews, I'd recommend this book written by a lead Google interviewer. It has 189 programming questions and solutions: