A clock is set right at 5 A.M. The clock loses 16 minutes in 24 hours. What will be the true time when the clock indicates 10 P.M. on the 4th day?

The true time is 11 PM.

From 5 AM on day 1 to 10 PM on day 4 the clock shows 89 hours.

The clock loses 16 min per 24 h, so 23 h 44 min shown = 24 h true.

True hours = 89 x (1440 / 1424) = 90 hours.

90 hours after 5 AM on day 1 is 11 PM on day 4.