Two trains leave a train station at the same time. One travels east at 11 miles per hour. The other train travels west at 9 miles per hour. In how many hours will the two trains be 70 miles apart?

11h + 9h = 70

Solve for h.

To find out in how many hours the two trains will be 70 miles apart, we'll first calculate their combined speed:

The train going east is traveling at 11 miles per hour, and the train going west is traveling at 9 miles per hour. To find their combined speed, we'll add these speeds together:

11 miles per hour + 9 miles per hour = 20 miles per hour

Now that we know the combined speed of the two trains is 20 miles per hour, we can determine the time it takes for them to be 70 miles apart by using the formula:

distance = speed × time

We want to find the time it takes for the trains to be 70 miles apart, so we'll rearrange the formula to solve for time:

time = distance / speed

Plugging in the given values:

time = 70 miles / 20 miles per hour

By dividing 70 miles by 20 miles per hour, we find:

time = 3.5 hours

Therefore, the two trains will be 70 miles apart in 3.5 hours.