A restaurant occupying the top floor of a skyscraper rotates as diners enjoy the view. Ling and Sarah notice that they began their meal at 7:00 p.m. looking due north. At 7:45 p.m. they had rotated 180° to a view that was due south. At this rate, how many degrees will the restaurant rotate in 1 hour?
The correct answer is C.
The restaurant is rotating 180° in 45 minutes. That means it is rotating 60° every 15 minutes.
That is 240° every 60 minutes or 1 hour.
Algebraically, you can set up a proportion:
180°/45 = x/60
x = 180° x 60/45
x = 240°.