1 rotation = 360 degrees
It takes 30 minutes.
It rotates (360/30) = 12 degrees every minute.
In 12 minutes, 1 seat will rotate (12 x 12) = 144 degrees.
============================================
A slightly different way to do it:
1 rotation = 360 degrees
It takes 30 minutes.
12 minutes = (12/30) = 0.4 of a complete rotation.
0.4 of 360 degrees = (0.4 x 360) = 144 degrees
============================================
A slightly different way to do it:
Set up the proportion:
(30 minutes / 360 degrees) = (12 minutes / 'x' degrees)
Cross-multiply the proportion:
30 x degrees-minutes = (12 x 360) degree-minutes
Divide each side by '30 minutes':
'x' degrees = (12 x 360 degree minutes) / 30 minutes = 144 degrees
