A clock goes slow from midnight by 5 minutes at the end of the first hour, by 10 minutes at the end of the second hour, by 15 minutes at the end of the third hour and so on. What will be the time by this clock after 6 hours?
(a)5.15 a.m.
(b)5.30 a.m.
(c)6 a.m.
(d)6.30 a.m.
Answer
Answer (as printed): B
Explanation
Time lost in 1 hour = 5 min. Time lost in 6 hours $=(5 \times 6) \mathrm{min}=30 \mathrm{min}$. After 6 hours, the correct time will be 6 a.m. and the clock will show 5.30 a.m.