At 9AM, two cars started from the same town and traveled north on the same road. One car averaged 45 miles per hour, and the other car averaged 40 miles per hour. In how many hours were the cars 30 miles apart?

The distance between them increases at a rate of 5 miles per hour.

Using that relative rate r,

r t = 5 t = 30
t = 6 hours

Follow the example of the problem I solved for you two posting below this.

The two problems are very similar.

Let me know what you got.

i don't get how to start on this one since it doesn't give how far apart the towns are. Well, there;s only one town- whatdo i do???

You don't have to know that, you know they are 30 miles apart.

So if you let the time be t hours, then the faster has traveled 45t miles, and the slower has traveled 40 t miles

The difference in the distance traveled is 30 miles, so....
45t - 40t = 30

5t=30

notice we now have the same equation that drwls obtained by simple common sense.

To find the time it takes for the two cars to be 30 miles apart, we can set up an equation using the distance formula: distance = rate × time.

Let's denote the time it takes for the cars to be 30 miles apart as "t" (in hours).

For the car traveling at 45 miles per hour, the distance it travels in time "t" is 45t.

For the car traveling at 40 miles per hour, the distance it travels in time "t" is 40t.

Since the cars are moving in the same direction, the distance between them is the difference between their respective distances: 45t - 40t.

We want this distance to be 30 miles, so we set up the equation:

45t - 40t = 30

Simplifying the equation, we have:

5t = 30

To solve for "t," we divide both sides of the equation by 5:

t = 30/5

t = 6

Therefore, it will take 6 hours for the two cars to be 30 miles apart.