Explanation:

At 5, the hands are 25 minutes spaces apart.
To get a right angle when the time is between 5.30 and 6, the minute hand has to gain (25 + 15) = 40 minute spaces over the hour hand.
In 60 minutes, minute hand gains 55 minute spaces over the hour hand.
Hence, to gain 40 minute spaces for the minute hand, time needed
=60/55×40=12/11×40 =480/11=43 7/11 minutes.
That means when the time is 43 7/11 minutes past 5, the hands of a clock will be at right angles.

Hence, option 3 is the correct answer.