Find the time between 8am and 9am when the hours and minutes hand would form a 90 degree angle betwe...........

Logical Reasoning(Master ) Clock

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Find the time between 8am and 9am when the hours and minutes hand would form a 90 degree angle between themselves.

27 5/11 past 8

27 3/11 past 8

29 8/11 past 8

29 5/11 past 8

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Explanation:

At 8pm hour hand and minute hand difference = 40 minutes

Here we have 2 possibilities -

1. To be at right angle, minute hand must be 15 minutes behind the hour hand
2. or it must be 15 minutes ahead of hour hand

In both these cases, it will form a right angle.

To be 15 minutes behind, minute hand must travel (40 - 15) = 25 minutes more
In 60 minutes, minute hand gains 55 min.
In ? minutes it gains 25 minutes

∴ ? =	25 x 60/	= 27	3/	minutes past 8 am
	55		11

For 15 minutes ahead, minute hand must travel (40 + 15) = 55 minutes more
In 60 minutes, minute hand gains 55 min.
So they will be at right angles again in 60 minutes past 8 pm i.e. exactly at 9 am.

Hence, option 2 is the correct answer.