Because the minute hand passes 6 degrees every minute and the hour hand passes 0.5 degrees.

If you start counting from 6 o'clock, the minute hand has passed X minutes, because the hour hand and the minute hand of the watch form a 90-degree angle. So:

1, 6x-0.5x = 90x = 180 at 6: 1 1, that is, the paper will be made from 6: 1 1: 180.

2,0.5x+360-6x = 90x = 540 divided by 1 1, that is to say, ending at 540 divided by 6 1 1.

So the time is (540 in 1 1 minus 1 1) minutes, which is 360 in 1 1, which is about 32.73 minutes.

I made it myself, there may be mistakes.