A clock is 4 minutes fast at 5:00 AM and 16 minutes fast at 5:00 PM. At what time (in AM) will it show the correct time?
Show answer & explanation
Correct answer: A
Explanation
Time from 5:00 AM to 5:00 PM = 12 hours = 720 minutes
During this time, the clock gains 12 minutes:
= 16 minutes - 4 minutes
= 12 minutes
That means, the clock gains 12 minutes in 720 minutes.
Now, to show the correct time, the clock must go from 4 minutes fast to 0 minutes fast.
Time to lose 4 minutes:
4/12 × 720
= 240 minutes
= 4 hours
4 hours before 5:00 AM:
= 1:00 AM
So, the clock will show the correct time at 1:00 AM.