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:

Question:
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	min. past 3
	12

[B].

4 p.m.

[C].

58	7	min. past 3
	11

[D].

2	3	min. past 4
	11

Answer: Option B

Explanation:

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

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

	37	hrs of this clock =	1	hrs of the correct clock.
	720		20

	37	hrs of this clock =		1	x	720	x	37		hrs of the correct clock.
	4			20		37		4

      = 9 hrs of the correct clock.

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