Many people would be daunted by this question at an interview and to be fair it doesn’t come up a lot in my experience however it worth knowing the answer in case.
The reason questions like these are used is not so the interviewer can see you squirm and they are not looking for the correct answer, they are merely looking to see how you demonstrate problem solving.
A strong candidate would be able to:
Evaluate and understand the problem Communicates assumptions Demonstrates analytic skills Answers the question. In case you want to know what the answer is:
As stated the answer is 22 – if you only count the minute and hour hands overlapping.
2 times a day when all 3 hands overlap – at midnight and noon.
A simple way to see this is to imagine that the two hands are racing each other round a track. Each time the minute hand laps the hour hand we have the overlaps we want.
How many times do a clockss hands overlap in a day? the answer is 22 and here is how:
1. midnight
2. 1 + 1/11 am
3. 2 + 2/11 am
4. 3 + 3/11 am
5. 4 + 4/11 am
6. 5 + 5/11 am
7. 6 + 6/11 am
8. 7 + 7/11 am
9. 8 + 8/11 am
10. 9 + 9/11 am
11. 10 + 10/11 am
12. noon
13. 1 + 1/11 pm
14. 2 + 2/11 pm
15. 3 + 3/11 pm
16. 4 + 4/11 pm
17. 5 + 5/11 pm
18. 6 + 6/11 pm
19. 7 + 7/11 pm
20. 8 + 8/11 pm
21. 9 + 9/11 pm
22. 10 + 10/11 pm
Thats a great question, bit like someone asking how many times a clock will tell the same time twice in the day. Obviously being a clock with hands that would be twice. Watch out for the alarm question too!
Interesting.