Answer: speed of the car is
40 miles per hour
speed of the turbopropeller is 230 miles per hour
Explanation:
Let x represent the speed of the car.
Let y represent the speed of the turbopropeller.
Time = distance / speed
Time travelled by Mattie Evans in his car is 120/x
It took the turbo propeller the same time to travel a distance of 690 miles.
Time it took the turbo propeller to travel 160 miles will be
690/y
Since the time is the same, then
120/x = 690/y
120y = 690x - - - - - - - - - 1
The speed of the plane was 190 mph faster than the car. This means that
y = x + 190- - - - - - - - - 2
Substituting equation 2 into equation 1, it becomes
120(x + 190) = 690x
120x + 22800 = 690x
690x - 120x = 22800
570x = 22800
x = 22800/570
x = 40 miles per hour
y = x + 190
y = 40 + 190 = 230 miles per hour