Aptitude - Clock - Discussion

Great this question was one of the mind buzzing.

And to tell you if you are taking opposite hands of watch as 12:30, 1:35 so on, then I am afraid your are wrong.

Because the hour hand won't be exactly on 12 if its 12:30, it will be at mid way of 12 and 1; and if its midway how can you put minute hand of watch on 12:30.

It should be somewhere around 12:32.5. Rest you can check manually.

@Rajneesh.

The hands are not in a straight line at 5.55. Take a hand watch and see for yourself. This is the point being made. From 4:50, the next occurrence happens only at 6:00.

So in total, for every 12 hours, we have 11 such instances. For 24 hours, the number of instances is 11*2=24.

Following are the time when they are straight.

12:30.
1:35.
2:40.
3:45.
4:50.
5:55.
6:00.
7:05.
8:10.
9:15.
10:20.
11:25.

And they are all 12.

Is I am missing something? How it is 11?

Take a watch rotate check it.

I want check. When in watch make time 2:45 pm that time which angle will be there.

Which angle a clock will make if both the needles are at 6.

I have a doubt. You all say the hour and minute hands are in straight line only once between 5 and 7. What about 5:55?

The time between 5 and 6 o'clock when two hands of a clock are in same line making angle of 180 degree?

The concept is we start from 12 they are one time opposite before 1 pm.

Similarly they will be opposite one more time before 2 pm. This is the condition till 5 pm but at 6 they are opposite at exactly 6 ( minute hand at 12 hour hand at 6 ) after this they will be opposite 7 times after 7 similarly opposite 11 times after 11 and 12 times after twelve gotcha after twelve so upto twelve only 11 times.

So in 24 hours 11+11 = 22 times.

In 60 min. 55 minute spaces are covered.

So lose of 5 min.

That is in 1 hour we lose 5 min.

So in 12 hour we will lose 12*5 = 60 min.

In 1 hour we will get only once when both the hands of watch will be in a straight line in opposite direction.

So we expect in 12 hour we should get 12 times both the hands be in a single straight line in opposite direction.

But unfortunately we have to minus the 1 hour that we have lost. That is one time we have to minus from 12 time.

That is in 12 hour we will have 12-1=11 time both the hand in straight line.

So finally in 24 hour we will get 22 times.