Aptitude - Clock - Discussion

I cant get the question what it means. Please someone try to explain it.

I can't understand this: (60/55*60) why this step is used. Please someone explain me?

Solution:

In 1 hour both the hands cover 55 min space.
=> 60/55 = 12/11 min space covered in 1min of the actual time.

for the hand to coincide hands have to cover 60 min space
=> 12/11 * 60 = 720/11 = 65.5/11 min in actual clock.

But the clock coincides every 64 min.
=>65.5/11 - 64 = 1.5/11 = 16/11 min loss in 64min.
=>16/11 * 1/64 = 1/44 min loss in 1min.

Loss In 24 Hrs => 1/44 * (24 *60) = 360/11 = 32.8/11 min the clock looses in a day.

Why we multiply 1/64 ?

How 55 spaces in 60 mins? couldnt get that.

What is this min. space?

Does it mean the min. hand lags the hour by 5 min. space ?

To coincide with each other space(ticks) between them should be ZERO(no space).

Consider starting from 12 noon.

in 1 hr--> min hand covers spaces(ticks) =60
in 1 hr--> hour hand covers spaces(ticks) = 5
so in 1 min --> hour hand covers 5/60=1/12 space(tick)

so after 1 hr=60 mins (1.00) spaces between them will be equal to 5
so have to cover 5 places for minute hand to meet hour hand
total time = 60+5 ... but in 5 mins hour hand will further go ahead by 5*1/12 ticks
so have to cover 5/12 ticks for minute hand to meet
total time = 60+5+5/12 ... but agin in 5/12 mins hour hand will go ahead buy 5/12*1/12= 5/12^2... and so on

So total time will be = 60+5+(5/12+5/12^2+5/12^3+.........) this GP
total time to meet = 720/11 i.e., 65.(5/11).

This time required to coincide hands in correct clock... solve accordingly.

How can the watch lose time if it is covering earlier than what is expected?

It is universal truth that watch does not lose any time.Every day start from 12:00 am in night, hr. and min hand positioned at 0 degree,than how lose? no lose is there..

But suppose hands coincide every 64 min.
(In really it is not possible..eg if ones they coincide it take 65+5/11 min always for next)
there will be lose of 65+5/11 - 64= 16/11 from actual or real time in 65+5/11 min.

So calculate lose in 1 day= 24*60 min

55 min. Spaces are gained by minute hand in 60 min period.

To find how many spaces it has actually gained, we need to fix a standard point first. !

With respect to it, we need to see the difference by how much is it actually varying. !

So let us assume the standard point to be the place where the minutes hand and hours hand has been coincided. !

I may be 12:00, 1.06, 2.11, 3.17. etc. from there. 60 minutes implies the minute hand must come back to the same point where it has started. !

Is it not. ?

Now, 60 minute passed and so minute hand covers 60 minute spaces.

And the hour hand advances by 5 minute spaces. !

So from the standard point fixed initially (we assumed the standard point is where the minute point and hours hand were coinciding. Also. 60 minutes will be passed when the minute hand comes back to the same position from where it started).

Now, there is.

An absolute 60 min spaces covered by minute hand in 60 min and then there is 5 min spaces advanced by hour hand in 60 min period. !

So on total.

Total advancement is 60-5 = 55 minute spaces. !