Puzzle – Flawed Clock

You have a clock that loses 10 minutes every hour. The clock is set correctly at noon. What time will the clock show when the correct time is midnight on the same day?

Flawed Clock

Solution:

• Since the clock loses 10 minutes every hour, after 1 hour, the clock will actually show 50 minutes past the correct time. After 2 hours, it will show 100 minutes past the correct time, which is 1 hour and 40 minutes. After 3 hours, it will show 2 hours and 30 minutes, and so on.
• So, to find out what time the clock will show at midnight, we need to determine how many hours have passed from noon to midnight, and then add the extra time due to the clock’s flaw.
• There are 12 hours from noon to midnight, so the clock will lose 10 minutes every hour for 12 hours, which adds up to a total of 120 minutes, or 2 hours.

Flawed Clock

Therefore, the clock will show 2 hours after midnight, which is 2:00 am.