1. Describe a person's "eight eyebrows" as "8: 20", that is to say, the hour hand and the minute hand should be symmetrical about the connecting line of "6" and "12" on the clock.

Every minute, the minute hand goes 6 degrees and the hour hand goes 0.5 degrees.

Symmetry, the minute hand angle is equal to 360 degrees if necessary.

So if you need to walk back for n minutes, the hour hand and minute hand can be symmetrical along the vertical line.

From 250-0.5N+ 120-6N=360, N= 1.54, which is about 1 minute and a half (not very detailed, otherwise it will include the influence of the movement of the second hand on the minute hand).

So the figure of the figure of eight eyebrows is about 8: 00, 18: 30.