Aptitude - Clock - Discussion

I think question should be "How much does a watch gain per day". Because lose means it loses 16/11 min from 65 (5/11).

Well Said @Manpreet, @Twinkle, @Abhilash.

But @Abhilash can you please elaborate how the step 64*55/60 came?

Formula for (720/11-m) (60*24/m)?

Direct formula:

Gain or loss = (720/11-m) (60*24/m).

Here m = 64,

Hence (720/11-64) (60*24/64) = (65.45-64) (45/2) = 1.45*22.5 = 32.625.

In 720/11 minutes.....incorrect clock gain (720/11-64) = 16/11.

In 1 minutes.....incorrect clock gain= (16/11)*(11/720).

In 24 hour.....incorrect clock gain = (16/11)*(11/720)*24*60.

= 32 min exactly.

Why it is not correct 24*4=96?

Using unitary method:

720/11 minutes of correct clock = 64 mins of incorrect clock.

Therefore 24*60 mins of correct clock = (64*24*60*11)/720 which gives 32 minutes exactly.

Where is discrepancy in this method?

How much can a watch gain or loss per day if its hand coincide every 65 minutes?

Can anyone explain this please?

Thanks in advance.

@ Shivangi is absolutely right. Check her explanation. Its easily explained.

Even now if you don't understand how 55 min are covered in 60 min then here is simple explanation.

Take it as a metaphor. Assume hour hand to be tortoise and minute hand to be hare. Now after 60 seconds you will see that hare had traveled 60 minute distance while tortoise had traveled only 5 minute distance. So you can say hare gained 55 minute or 55 spaces to tortoise. So finally you can say minute hand gained 55 spaces to hour hand.

Gain or loss per day = (720/11-m) (60*24/m).

M: Interval at which minute hand overtake the hour hand.

If result positive indicate positive otherwise negative.

= (720/11-64) (60*24/64).

= (16/11) (60*24/64).

= 32 (8/11).