Aptitude - Clock - Discussion

Discussion Forum : Clock - General Questions (Q.No. 4)
4.
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:
59 7 min. past 3
12
4 p.m.
58 7 min. past 3
11
2 3 min. past 4
11
Answer: Option
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.

Discussion:
154 comments Page 12 of 16.

Vivek said:   9 years ago
No Need to use such a long method.

In 3 mins it's gaining 5 sec.
Io in 1 min the gain take = 5/3.s
And in 60 min it's going to gain = (5/3) * 60= 100 s.
Now the difference between two times is 9 : 15 hrs.
And in 9 hrs it's going to gain 100 * 9 = 900 s.

900 /60 = 15 min.

So at 4 : 15 it's already 15 min ahead so real time will be 4.

Gjm said:   9 years ago
Simple friends time 7 am to 4.15 pm.
1st we take time 7am to 8am that means 60 min but give its gain 5 sec in 3 min so 60/3 = 20 mins.

Then 20 min * 5 sec = 100 sec that means 1.40 min per 1 hour so now we calculate 7am to 4:15pm, 9 hours = 15 min 4:15 - 0:15 = 4 pm.

Yashpal said:   9 years ago
You are totally wrong @Gjm.

You can't multiple two different units of time without converting them i.e. 20 min * 5 sec = 100 sec is not possible it could be (20 min/60) sec * 5 sec = whatever.

Yashpal said:   9 years ago
Agree with you @Nitin.

The correct answer is A.

Sarthak said:   9 years ago
185 seconds to 9hr 15 minute how?

Durgesh said:   9 years ago
A clock is set right at 10 a.m the clock gains 10 minutes in 24 hours .what will be the true time when the clock indicates 3 p.m the following day?

Please solve it.

Rijas Das said:   9 years ago
Why are you calculating it in the hour? why not in minutes?

Both the answers are different. Make it clear.

Ashok Apple said:   8 years ago
Thank you @Natasha.

Sushma said:   8 years ago
Nice explanation, Thank you @Sundar.

Praveen said:   8 years ago
@Sundar.

How it should be 555 min/3 min 5 sec [or] 33300/185"?

It must be divided by 3min right, not 3 min 5 sec.

How you are saying it must be divided by 3min 5 sec?


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