A clock is 5 minutes fast at 11:30 AM and 11 minutes fast at 11:30 PM. At what time (in AM) will it show the correct time?
Show answer & explanation
Correct answer: A
Explanation
Hourly Rate of Gain:
12 = 6
1 = 6 / 12 = 0.5 (30)
Time Required for a 5-Minute Gain: How long would it have taken for the clock to run 5 minutes fast?
5 / 0.5l = 10
Calculation of the Correct Time: Since the clock was already 5 minutes fast at 11:30 AM, this implies that it was displaying the correct time 10 hours earlier.
11:30 AM – 10 hours
Counting back 10 hours from 11:30 AM brings the time to 1:30 AM.
Conclusion
The clock will show the correct time at 1:30 AM.