A clock is set right at 6 a.m. The clock loses 16 minutes in 24 hours. What will be the true time when the clock indicates 10 p.m. on 4th day?      

     Time from 5 a.m. on a day to 10 p.m. on 4th day = 89 hours.

     Now 23 hrs 44 min. of this clock = 24 hours of correct clock.

     356/15 hrs of this clock = 24 hours of correct clock.

     89 hrs of this clock = (24 x 31556 x 89) hrs of correct clock.

                              = 90 hrs of correct clock.

     So, the correct time is 11 p.m.