Question

Jon recently drove to visit his parents who live 480 480 miles away. On his way there his average speed was 20 20 miles per hour faster than on his way home (he ran into some bad weather). If Jon spent a total of 20 20 hours driving, find the two rates.

Answer 1

Jon's speed on the way home was 12 mph and on the way there was 32 mph.

Step-by-step explanation:

To find the two rates, let's set up a system of equations. Let's assume Jon's speed on his way home was x miles per hour.

According to the problem, his speed on the way there was 20 miles per hour faster, so his speed on the way there was x + 20 mph.

We know that the total time spent driving was 20 hours. Using the formula distance = rate * time, we can set up the following equations:

x * t = 480

(x + 20) * t = 480

Where t is the time spent driving on each trip. Now we can solve the system of equations:

x * t = 480

x * 20 = 480 - 20x (from substituting the first equation into the second)

x * 20 = 480 - 20x

20x + x * 20 = 480

40x = 480

x = 12

So Jon's speed on the way home was 12 mph and on the way there was 12 + 20 = 32 mph.