Microsoft Gold Bar Puzzle: Pay 7 Days [Solved]

Answer: Cut the 7 piece gold bar into pieces of 1, 2, and 4, using only two cuts, and use change to pay exactly one piece per day. The Microsoft gold bar puzzle asks how you pay a worker for 7 days when you can cut a 7 piece gold bar only twice. This split is the whole trick, because 1, 2, and 4 can combine to make every total from 1 to 7.

A worker agrees to work for 7 days. You will pay one piece of gold at the end of each day. The bar has 7 equal pieces joined in a row. You may cut it only twice, so you end with 3 pieces in total. You may also take pieces back as change during the week. How do you pay the worker exactly one piece per day, every day, without ever overpaying or underpaying?

Most candidates start with the wrong goal. They try to cut the bar into 7 single pieces, which needs 6 cuts. The puzzle allows only 2 cuts, so that route fails at once. A strong candidate pauses and asks a different question: what 3 piece sizes can add up to every daily total? That question leads straight to 1, 2, and 4.

How the Microsoft Gold Bar Puzzle Works

First, cut the bar after the first piece and after the third piece. You now hold a 1 piece, a 2 piece, and a 4 piece. Together they still total 7 pieces, but you can hand them over and take them back in different combinations. Each evening, the worker must hold exactly the number of pieces equal to the number of days worked. The table below shows the full week.

End of day	Give the worker	Take back	Worker now holds
Day 1	1 piece	Nothing	1
Day 2	2 piece	1 piece	2
Day 3	1 piece	Nothing	3
Day 4	4 piece	1 piece and 2 piece	4
Day 5	1 piece	Nothing	5
Day 6	2 piece	1 piece	6
Day 7	1 piece	Nothing	7

Walk through the middle of the week slowly, because that is where candidates slip. On day 4, you hand over the 4 piece and take back the 1 piece and the 2 piece. The worker gives up 3 pieces and gains 4, so the net holding moves from 3 to 4. On day 6, the same pattern repeats at a smaller scale: you hand over the 2 piece and take back the 1 piece, so the holding moves from 5 to 6. Every move keeps the total exact.

Why 1, 2, and 4 Cover Every Total

These three numbers work because each one is double the one before it. With 1 alone, you can make 1. Add 2, and you can make 2 and 3. Add 4, and you can make 4, 5, 6, and 7. No total is missing, and no total needs a piece you do not hold. In short, 1 plus 2 plus 4 equals 7, and every number below 7 has its own combination.

Try a different split to see why this matters. A 1, 3, and 3 split also totals 7, but it fails on day 2, because you cannot make 2 from 1 and 3 without overpaying. A 2, 2, and 3 split fails on day 1, because you hold no single piece. Only the doubling split covers all 7 totals with no gaps. That property has a name in computing: binary counting, where each place value doubles. You do not need that term in the interview, but the pattern is worth naming if the interviewer asks why you chose these sizes.

The Trap Most Candidates Fall Into in the Microsoft Gold Bar Puzzle

The first trap is cutting for the week you can see, not the week you must pay. Candidates picture 7 separate daily payments and reach for 7 pieces. Interviewers watch for that move, because it shows a candidate solving the easy version of the problem instead of the real one. State the constraint out loud before you cut anything: only two cuts, only three pieces, exact pay every day.

The second trap is forgetting that change counts. Some candidates find the 1, 2, and 4 split but then freeze on day 2, because they think giving the 2 piece means the worker now holds 3. Say the take-back step in the same breath as the give step. “I give the 2 piece and take back the 1 piece, so the worker holds 2.” That one sentence removes the confusion.

The third trap is a clever shortcut that breaks the rules. Bending or folding the bar to cut 7 pieces with 2 cuts sounds creative, but it changes the problem. The bar is a row of 7 joined pieces, and the cuts run between pieces. If you want to show creativity, show it in the payment plan, not by rewriting the puzzle. Interviewers reward candidates who respect constraints and still find a clean answer.

What the Interviewer Is Testing in the Microsoft Gold Bar Puzzle

First, the interviewer is testing whether you can reframe a problem. The puzzle looks like a cutting problem, but the real problem is a combination problem. A candidate who asks “what totals must I make?” has already moved past the surface of the question.

Second, the interviewer is testing whether you handle change and net totals with care. Finance, operations, and consulting work all run on net positions, not gross moves. Handing over 4 while taking back 3 is a net payment of 1, and a candidate who tracks that net number clearly shows a useful working habit.

Third, the interviewer is testing how you explain a pattern. The 1, 2, and 4 split is not a guess you memorized. You can justify it in one line: each piece doubles the last, so the combinations cover every total up to 7. A clear justification matters more than a fast answer, because it proves you could adapt the same idea to a longer bar or a different total.

Finally, the interviewer is listening for structure. Lead with the answer, show the day by day table, then explain why the split works. That order tells the interviewer you have the result and the reasoning, not just a trick you once heard.

Try a Longer Version Next

Once the 7 day version is clear, test the pattern on a longer bar. A 15 piece bar needs only 4 pieces: 1, 2, 4, and 8. A 31 piece bar needs 5 pieces: 1, 2, 4, 8, and 16. Each time, the number of pieces grows slowly while the bar grows fast. That is why the doubling idea is powerful, and it is a good closing line if the interviewer asks where the idea generalizes.

Frequently Asked Questions

Can you pay a worker for 7 days with only two cuts?

Yes. Cut the bar into 1, 2, and 4 pieces, then use change each evening so the worker holds exactly 1, 2, 3, 4, 5, 6, and finally 7 pieces across the week.

Why not cut the bar into 1, 3, and 3 pieces?

That split totals 7, but it cannot make 2 without overpaying, because you hold no 2 piece and 3 is too much on day 2. Only 1, 2, and 4 cover every total from 1 to 7.

Is this puzzle really asked at Microsoft?

Candidate reports and Microsoft interview question lists describe this gold bar payment question as a classic Microsoft riddle, used to test reasoning rather than technical knowledge. The wording varies across reports, but the 7 day setup and the two cut limit stay the same.

Try another classic next: Water Jug Puzzle Answer: Measure 4 Litres [Solved], or test the box trick in Mislabeled Boxes Puzzle Answer: One Fruit [Solved], or work through the coin trick in Apple 100 Coins Blindfolded Puzzle Answer [Solved].