Clock: A clock goes slow from midnight by 5 mts. at the end of the first hour, by 10 mts. at the end of the second hour, by 15 mts. at the end of the 3rd hour and so on. What will be the time by this clock after 6 hours?

The clock loses time progressively—5 minutes after the first hour, 10 minutes after the second, 15 minutes after the third, increasing by 5 minutes each hour. After 6 hours, the total time lost is 5 + 10 + 15 + 20 + 25 + 30 = 105 minutes, which equals 1 hour and 45 minutes. Therefore, when the actual time is 6:00 a.m., the slow clock will show 6:00 minus 1 hour 45 minutes, which is 4:15 a.m.