1.

At what time after 7:00 pm will the hands of the clock be opposite to each other?

Answer»

Just at 7.00pm the hour hand is at 7 and minute hand is at 12.

Each minute division makes 6 at the center. So at 7.00 pm a reflex angle of 210 will be formed between hour hand and minute hand because the hour hand will be at 35 minute divisions ahead of minute hand.

Let x minute after 7.00pm the hands of the clock will be opposite to each other.Then the angle between the hands will be 180

We know hour hand rotates 360 in 12hr or 720 minutes

So in x minute the hour hand will increase the reflex angle by 360x720=(x/2)

In this x minute the minute hand will decrease the reflex angle by (6x) .

Hence

210+(x/2)−(6x)=180

⇒x=(60/11) minute

So at 7 past 55/11minute the hands will become opposite to each other.



Discussion

No Comment Found

Related InterviewSolutions