Okay so this is how I would do it but you can do it a different way
160/2 = 80 (2 b/c I want a whole # and 2 is a factor of 6 & 20)
so 80 degree in 2 seconds
so then 80 *10=800 (10 b/c 20/2=10)
but since there's only 360 degrees in a full circle
800/360=2.22
so we go back to 80 *2.22=177.6 degrees
-----------------------------------------------------------------------
v.s. 160 n
---- * --- (20 *160=3200/6=533.33
6 20
You can go w/ whatever answer you think is right b/c frankly I don't know but if I were you I would go with the second one because it seems more right and there's actually a method to the madness.