Aptitude - Clock - Discussion

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.

How we are getting after calculation 4min 48 sec in denominator i.e. (5?).

I understood 4*60=240 but I am not getting that how 5 came in the denominator.

Please, anyone help me. Thanks.

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.

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 >?

Thank you all for the given explanation.

Thank you everyone.

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.

Explain me clearly to get it.

Very helpful. Thanks a lot @Akash.

@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.