Aplane flies at 200 mph for the first and last half hour of a flight. it flies at 400 mph the rest of the time. the route is 1000 miles long. the town of erehwon is on the route 300 miles before the end. what is the distance of the plane from erewhon after t hours of flying?

Explanation:

As we know that the distance moved by the plane is 1000 miles

So here we know that plane speed is 200 mph in first and last hour of the flight

So we will have

now we know that the remaining distance which it will cover with 400 mph speed is given as

so time taken by it to cover that distance is

so the plane will reach the position of Erehwon at time