In 60 minutes, hour hand will move 5-minute spaces while the minute hand will move 60-minute spaces. Gain of 55-minute spaces = 60minutes Gain of 15-minute spaces =
60
55
×15=16
4
11
minutes. This is the number of minutes after which minute hand and hour hand coincide. Now, after further 16
4
11
minutes, the minute and hour hand would be at right angle. Therefore, time after 3 o’clock, the hour hand and minute hand are at right angle. =3hours+16