A watch which gains 15 seconds in 9 minutes was set right at 8 a.M. In the afternoon of the same day, when the watch indicated quarter past 5 o’ clock, the true time is?
Answers
The true time is 5 p.m
Given,
A watch gains 15 seconds in 9 minutes.
The time was set right at 8 a.m.
To Find,
The true time when the watch indicated a quarter past 5 o'clock =?
Solution,
Watch gains seconds in 9 minutes = 15 seconds
Watch gains seconds in 1 minutes = 15/ 9 = 5 / 3 seconds
The time difference between 8 a.m. and 5:15 p.m. = 9 hours 15 minutes
The time difference between 8 a.m. and 5:15 p.m. = 9*60 + 15 minutes
The time difference between 8 a.m. and 5:15 p.m. = 555 minutes
Total time difference in 555 minutes = (5 / 3) * 555
Total time difference in 555 minutes = 925 seconds
Total time difference in 555 minutes = 925 / 60 minutes
Total time difference in 555 minutes = 15.41 minutes
The true time = 15.41 minutes before quarter past 5 o'clock
The true time = 5 p.m. approx
Hence, when the watch indicated a quarter past 5 o'clock, the true time is 5 p.m.