Aptitude - Clock - Discussion

Discussion Forum : Clock - General Questions (Q.No. 19)
19.
A watch which gains uniformly is 2 minutes low at noon on Monday and is 4 min. 48 sec fast at 2 p.m. on the following Monday. When was it correct?
2 p.m. on Tuesday
2 p.m. on Wednesday
3 p.m. on Thursday
1 p.m. on Friday
Answer: Option
Explanation:

Time from 12 p.m. on Monday to 2 p.m. on the following Monday = 7 days 2 hours = 170 hours.

The watch gains 2 + 4 4 min. or 34 min. in 170 hrs.
5 5

Now, 34 min. are gained in 170 hrs.
5

2 min. are gained in 170 x 5 x 2 hrs = 50 hrs.
34

Watch is correct 2 days 2 hrs. after 12 p.m. on Monday i.e., it will be correct at 2 p.m. on Wednesday.

Discussion:
56 comments Page 3 of 6.

Rahul said:   10 years ago
How it is 85/204?

Ayush aryan said:   9 years ago
Great explanations. Thank you all.

Pratik said:   9 years ago
Great explanation @Madhu.

Beatrice Abongo` said:   9 years ago
What will be the answer for the question?

A watch loses 5 seconds every 2 hours it is set on Wednesday at 10:00 am what time will it show the following Wednesday at 10:00 am?

Akash Vashista said:   9 years ago
Here, the clock was late by 2 min. And then it gains 4 min 48 sec. Means we have to cover 2 min time as well as 4 min 4 sec time also.

Therefore total gain = 2 + 24/5 = 34/5 min in 7 days 2 hrs (170 hrs).

Here, extra 2 min of which we are a late need to be covered to make the time correct are gained in.

Therefore 34/5 min = 170.

1 min = 170 * (5/34),

2 min = 2 * 170 * (5/34),

2 min = 50 hrs.

i.e 2 days 2 hrs from Monday which is Wednesday 2 pm.

Sonai said:   9 years ago
Thank you everyone.

Prateek said:   9 years ago
Thank you, @Akash.

Apoorva said:   9 years ago
We added 2 min to 4 min and 48 sec because the word gain was specified.

What can B the variation in question that will make us subtract 2 min from 4 min and 48 sec?

Darshit said:   9 years ago
Did'nt get it, please explain it once more and elaborate it.

Piyush said:   9 years ago
2 min are gained in.

170 x (5/34) x 2 hrs = 50 hrs.

Can you please explain this.

Actually, my question is why we have multiplied "2" here?


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