A clock is set right at 5 a.m. The clock loses 16 min in 24 h. What time will be right time when the clock indicates 10 p.m. on the 4th day?
Answer & explanation
Correct answer: option 3
The correct answer is Option (3) → 11:00 p.m.
A clock that loses time runs slow at a steady rate, so the time it shows and the correct time always stay in the same ratio. In every 24 h of correct time this clock shows only 24 h − 16 min = 23 h 44 min, and it was set right at 5 a.m., so both start together.
Ratio of time shown to correct time: 23 h 44 min : 24 h \(=1424:1440=89:90\)
Time the clock shows from 5 a.m. on the 1st day to 10 p.m. on the 4th day: 3 days (72 h) + 17 h \(=89\) h
For every 89 h the clock shows, 90 h really pass, so the correct time passed is 90 h
90 h \(=3\) days 18 h, and 5 a.m. on the 1st day + 3 days 18 h \(=\) 11 p.m. on the 4th day