A Plane Can Fly 540 Miles with the Wind in One

Multiple Choice

A plane can fly 540 miles with the wind in one hour less than it can fly 480 miles against the wind. The average wind speed is 30 miles per hour. Find the speed of the plane in still air.

A) 120 miles per hour
B) 150 miles per hour
C) 180 miles per hour
D) 210 miles per hour