It can be found that every time the minute hand moves 360 degrees, the hour hand moves 30 degrees, that is, every time the minute hand moves 6 degrees (1 min), it catches up with the hour hand 1 1/2 degrees.

The right angle, the minute hand and the hour hand form 90 degrees, which are discussed in two cases.

1, the minute hand hasn't caught up with the hour hand.

( 150 -90)/( 1 1/2) = 120/ 1 1

So the time is 5:10:10/1.

That is, 5 hours 10 minutes and 54.5455 seconds.

2. The minute hand exceeds the hour hand

( 150 +90)/( 1 1/2) = 480/ 1 1.

So the time is 5: 43: 7/ 1 1.

That is, 5 hours, 43 minutes and 38. 18 18 seconds.