A watch which gains 5 seconds in 3 minutes was set right at 7 a.m. In the afternoon of the same day, when the watch indicated quarter past 4 o'clock, the true time is:

A 59(7/12) min. past 3

B 4 p.m.

C 58(7/11) min. past 3

D 2(3/11) min. past 4

Correct Answer: Option B

Time from 7 a.m. to 4.15 p.m. = 9 hrs 15 min. = 37/4 hrs.

3 min. 5 sec. of this clock = 3 min. of the correct clock.

=> 37/720 hrs of tjis clock = 1/20 hrs of the correct clock.

=> 37/4 hrs of this clock = (1/20×720/37×37/4) hrs of the correct clock.

= 9 hrs of the correct clock.

So, the correct time is 9 hrs after 7 a.m. i.e., 4 p.m.