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?
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 |
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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 2 of 6.
Akash Vashista said:
10 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.
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.
(1)
Malli said:
1 decade ago
Please anybody explain me the gain and loose concept of the clock. I thought we should subtract 2 mins from 4 mins 4 sec. So we can calculate actual gain, so how we add both loss and gain of time >?
(1)
Koya said:
9 years ago
Sam sets alarm at 5 am. But the clock loses 16 minutes in 24 hours. Effectively, the clock indicates 10:00 pm on the 4th day. Find out the original time of the clock.
Tell me the answer for this question.
Tell me the answer for this question.
(1)
Gautam said:
6 years ago
@Nitin
Initially, it is 2 min low at 12 pm so to compensate that loss 2min gain is there but at last, why do they calculate for 2 min gain individually? Explain it.
Initially, it is 2 min low at 12 pm so to compensate that loss 2min gain is there but at last, why do they calculate for 2 min gain individually? Explain it.
(1)
Nitesh Nandwana said:
2 decades ago
@Vinesh
The question isn't that 2 min should be added or subtracted, the question is that why are we doing so ? got it ??
"gains uniformly is 2 minutes low". It means clock is 2 min late at noon on Monday Okay ?
Now on next Monday it is 4 min 48 sec fast means it total gain is
= ( 2 min + 4min 48sec)
The question isn't that 2 min should be added or subtracted, the question is that why are we doing so ? got it ??
"gains uniformly is 2 minutes low". It means clock is 2 min late at noon on Monday Okay ?
Now on next Monday it is 4 min 48 sec fast means it total gain is
= ( 2 min + 4min 48sec)
(1)
Pushpa said:
10 months ago
I am not understand the answer. Please anyone help me to get this.
(1)
Tamizharasi said:
9 years ago
Thank you all for the given explanation.
Sakshi said:
9 years ago
@Piyush,
It's unitary method.
34/5 mins are gained in 170 hrs.
So 1 min is gained in 170 * 5/34 hrs.
So 2 mins are gained in 170 * 5/34 * 2 hrs.
It's unitary method.
34/5 mins are gained in 170 hrs.
So 1 min is gained in 170 * 5/34 hrs.
So 2 mins are gained in 170 * 5/34 * 2 hrs.
Karthik said:
9 years ago
Gain means the clock's hands are moving fast than actual time (i.e it takes less than 60minutes for minute's hand to complete 360 degrees).
Initially, the time in given clock is 11:58am but the actual time is 12 pm (this might be because someone changed the time to 11:58 in given clock).
Since the clock is moving fast it's time is 4min 48sec fast on following Monday. Now at one point in between present Monday to next Monday the given clock's time coincides with normal clock's time (i.e correct time). Now total time from 12 pm to next Monday 2pm is 170hours. Total time gain by given clock = 2+ (4min 48sec) = 34/5min in 170 hours. What we need now is 'When it shows the correct time. ' If clock gains those 2minutes which it is lagging initially then it shows the correct time. 34/5min gain in 170hours then 2min will gain in 170*2* (5/34) hours.
Initially, the time in given clock is 11:58am but the actual time is 12 pm (this might be because someone changed the time to 11:58 in given clock).
Since the clock is moving fast it's time is 4min 48sec fast on following Monday. Now at one point in between present Monday to next Monday the given clock's time coincides with normal clock's time (i.e correct time). Now total time from 12 pm to next Monday 2pm is 170hours. Total time gain by given clock = 2+ (4min 48sec) = 34/5min in 170 hours. What we need now is 'When it shows the correct time. ' If clock gains those 2minutes which it is lagging initially then it shows the correct time. 34/5min gain in 170hours then 2min will gain in 170*2* (5/34) hours.
Anu said:
9 years ago
Very helpful. Thanks a lot @Akash.
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