A jet flies over the Air Force Base at 10:20 a. m. At 10:32 a. m., the plane passes over the Navy Base Station, 120 miles away. How fast is the aircraft traveling?

So first calculate the time between the plane flied over the Air Force Bases (AFB) and Navy Base Station (NBS):
(time passed Air Force Bases) - (time passed Air Force Bases) = 10:32 - 10:20 = 12 mins
Since we know the distance that plane travel from AFB to NBS is 120 miles and the plane traveled that distance within 12 minutes.
We have
120 miles / 12 minutes = 10 miles / minute
Calculate it into miles per hour (60 minutes):
10 miles/minute x 60 minutes = 600 miles per hour.
ANSWER : 600 mph