A watch which gains uniformly in 5 min slows at 8 o? clock in the morning on Sunday and it is 5 min 48 sec fast at 8 pm on the following Sunday. When was it correct?
Answer: C
Time from 8 am on Sunday to 8 pm on following Sunday = 7 days 12 hours
= 180 hours
∴ The watch gains (5 + 29/5) min or 54/5 min in 180 hours.
Now 54/5 minutes are gained in 180 hours.
∴ 5 minutes are gained in [180*(5/54)*5] hour = 83 hr 20 min
= 3 days 11 hours 20 minutes
Watch is correct 3 days 11 hours 20 minutes
after 8 AM of Sunday i.e. 7:20PM on Wednesday.