Timed timed an object travels in a circular path that has a diameter of 4 feet. the object makes 1,320 revolutions per hour. what is the linear velocity, in miles per hour, of this object a. pi b. 2pi c. 5280 pi d. 10560 pi

We know that
circumference=pi*D
where D is the diameter
diameter=4 ft
circumference=4*pi ft
if one revolution is > 4*pi ft
1320 rev> x
x=1320*4*pi> x=5280*pi ft/hout

convert ft to miles
1 mile> 5280 ft
so
5280*pi ft> is pi mile
5280*pi ft/hour> is equal to pi mile/hour

the answer is the option 
a. pi