26. Ranjit Kumar purchased a new watch in Burma Bazaar. Sooner he found that the uniformly gaining watch starts with a lag of 2 minutes at noon on a particular Monday and it is 4 minutes 48 seconds fast at 2PM on the following Monday. Please guide Ranjit Kumar when the clock would show the true time ?
(a)2PM on Tuesday
(b)2PM on Wednesday
(c)3PM on Thursday
(d)1PM on Friday
Answer : b)2PM on Wednesday
Explanation:
12 noon Monday to 2PM next Monday is 7 days and 2 hours. i.e. 7 x 24 +2 = 170 hours.
The new watch purchased by Ranjit Kumar was 2 minutes slow and by 170 hours it was fast by 4 minutes 48 seconds. (4 minutes 48 seconds can be written as 4 48/60 or 4 4/5 minutes.)
Therefore total gain in 170 hours = 2 minutes + 4 4/5 minutes = 34/5 minutes = 408 seconds
Gain per hour = 408/170 = 2.4 seconds.
It is given the watch was slow by 2 minutes (120 seconds) initially. Therefore the time at which the watch will make up for the lost 2 minutes by gaining 2 minutes or 120 seconds will be our answer.
2.4 seconds is gained in 1 hour.
120 seconds will be gained in 1/2.4 x 120 =50 hours.
So the watch will show right time in 50 hours from Monday 12.00 noon ie at Wednesday 2.00 PM.