Answer:
1,200 cars per hour
Step-by-step explanation:
Let's suppose the car flow is constant and based on the observations stated in the problem.
If we set and imaginary car counter where your car is, then there are 25 cars in ¼ of a mile (including yours) going at your same speed.
Now compute how long it will take to travel ¼ mile. As your speed is constant 60 mph, we can cross multiply
60 miles -----------> 1 hour
¼ of a mile --------> x hours
and
60/ (¼) = 1/x ---------> x = 1/240 hours.
This means that in 1/240 hours the 25 cars will be passing the counter.
Now compute how many cars will pass through our counter in 1 hour. Again, cross multiplying
1/240 hours -------> 25 cars
1 hour --------------> x cars
and
1/240 = 25/x -------> x = 25*240 = 1,200 cars.
So, the flow rate of the highway (going in your direction) in cars per hour is 1,200 cars per hour.
