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