Question

50. Two airplanes leave the airport at the same time, flying in opposite directions. One plane flies 100 miles per hour faster than the other. They fly for 4 hours and end up 2,000 miles apart. How fast do they each fly? 150 mph and 250 mph 200 mph and 300 mph 300 mph and 400 mph 225 mph and 325 mph

Answer 1

First take the 2,000 miles, and subtract 400 from it (You do this because one plane is going 100 miles faster then the other for 4 hours) = 1,600 miles, then divide the 1,600 miles by 2 (because there are 2 planes moving apart from each other) you then get 800 miles. Take the 800 and divide that by 4 (they were flying for 4 hours) = 200 mph. We now know that one of the planes is flying 200 mph, and the other plane is flying 300 mph (because one is faster then the other by 100 mph, also don't forget your units) Hope this helps :)

Answer 2

Answer: Two speeds are 300 mph and 200 mph.

Step-by-step explanation:

Since we have given that

Distance between two airplanes = 2000 miles

Time taken by them = 4 hours

Let the speed of first airplane be 'x'.

Let the speed of second airplane be 'y'.

So, Relative speed of both airplanes moving in opposite direction = x+y.

As we know the relation between Distance, time and speed.

$\dfrac{Distance}{Time}=Speed\\\\\dfrac{2000}{4}=x+y\\\\500=x+y-----------------(1)$

According to question we have given that

One plane flies 100 miles per hour faster than the other.

So, it becomes

$x-y=100-----------------(2)$

Using elimination method, we get that

$x+y=500\\\\x-y=100\\\\--------------------------\\\\2x=600\\\\x=\dfrac{600}{2}\\\\x=300\ miles/hr$

So, we put the value of x in x+y=500, we get the value of 'y'.

$300+y=500\\\\y=500-300\\\\y=200\ miles/hr$

Hence, two speeds are 300 mph and 200 mph.