Final answer:
The speed of the plane in still air is 480 mph, and the speed of the wind is 70 mph.
Step-by-step explanation:
Let's assume the speed of the plane in still air is x mph and the speed of the wind is y mph.
When flying with the wind, the speed of the plane is x + y mph. Therefore, we can write the equation:
x + y = 550
When flying against the wind, the speed of the plane is x - y mph. Therefore, we can write the equation:
x - y = 410
Solving these two equations simultaneously, we can find the values of x and y.
Adding the two equations: (x + y) + (x - y) = 550 + 410
2x = 960
x = 480
Substituting the value of x into one of the original equations, we can find the value of y.
480 - y = 410
y = 70
Therefore, the speed of the plane in still air is 480 mph, and the speed of the wind is 70 mph. So the correct answer is (a) Plane speed = 480 mph, Wind speed = 70 mph.