Answer: the speed of the plane is 130 mph
Step-by-step explanation:
Let x represent the speed of the plane. If the car travels 80 mph slower than the plane, then the speed of the car would be (x - 80) mph.
Time = Distance/speed
plane can fly 520 miles in the same time as it takes a car to go 200 miles. This means that the time it takes the plane to fly 520 miles is
520/x
Also, the time it takes the car to drive 200 miles is
200/(x - 80)
Since the time is the same, it means that
520/x = 200/(x - 80)
Cross multiplying, it becomes
520(x - 80) = 200 × x
520x - 41600 = 200x
520x - 200x = 41600
320x = 41600
x = 41600/320
x = 130 mph
