Question

Two jet planes simultaniously started traveling in opposite directions from the same airport. Four hours later, they where 3800 miles apart. Find the rate of each plane if one of them traveled 80 miles per hour faster than the other

Answer 1

435 miles per hour, 515 miles per hour

Step-by-step explanation:

Let us assume that plane A is traveling at 'x' miles per hour, then plane B is traveling at 'x+80' miles per hour. As the question says that one of them traveled 80 miles per hour faster than other.

After 4 hours they were 3800 miles apart.

We know that,

$t = \frac{distance}{speed}$

Since two planes are traveling in opposite directions, so we will add their speed.

Putting the values in the equation we get,

$4 = \frac{3800}{x + (x + 80)}$

Now, solving for 'x'

$4(x + (x + 80) = 3800$

$4x + 4x + 320 = 3800$

$8x = 3800 - 320$

$8x = 3480$

$x = \frac{3480}{8} = 435$

So the rate of plane A is 435 miles per hour and the rate of plane B is (435+80 = 515) miles per hour.