Mattie Evans drove 250 miles in the same amount of time that it took a turbopropeller plane to travel 1250 miles. The speed of the plane was 200 mph faster than the speed of the car. Find the speed of the plane

3 answers

its 450 mph
Speed = distance/time

time = distance/speed

Let x = plane speed and y = driving speed

y = x + 200

250/x = 1250/y

Substitute x + 200 for y in second equation and solve for x. Insert that value into the first equation and solve for y. Check by inserting both values into the second equation.
Car speed = X-mi/h,
Plane speed = (X + 200) mi/h,

Eq1: d1 = X*t = 250 mi,
t = 250 / X,

Eq2: d2 = (X + 200)t = 1250 mi.

Substitute 250 / X for t in Eq2:
(X + 200)250/X = 1250,
250 + 50000/X = 1250,
50000 / X = 1250 - 250,
50000 / X = 1000,
Cross multiply:
1000X = 50000,

X = 50000 / 1000 = 50 mi/h = car speed.
(X + 200) = 250 mi/h = plane speed.