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

The correct option is D 11 p.m.
Time from 5 a.m. on a day to 10 p.m. on 4th day is 89 hours.

Now,

24 hours - 16 mins = 23 hrs. 44 min. of this clock are the same as 24 hours of the correct clock.
i.e., $\frac{356}{15}hrs.$ of this clock =24 hrs. of correct clock.
$\therefore 89$ hrs. of this clock $=\frac{24\times 15}{356}\times 89hrs.$ of correct clock = 90 hrs of correct clock.

So, the correct time is 11 p.m.