Walking in minutes is 360 degrees. At this time, the hour hand walks a number at an angle of 360/ 12=30 degrees, the minute hand walks a number at an angle of 360/60= 6 degrees per minute, and the hour hand walks a number at an angle of 30/360 =112,6544.

6x-(x/ 12)*6= 180-30

6x-x/2= 150

1 1x/2= 150

x=300/ 1 1

x=27.27

At 27.27 minutes of 1 1, the hour hand and the minute hand just form a right angle.