Chapter 3.5, Problem 4A

For the first question, we’ll provide some suggestions on how to proceed. Of course, if you can think of a different way that works for you, that’s not just okay, it’s GREAT.

On the way to the airport a few years ago, my wife’s car hit a huge hole in a construction area, damaging the front right wheel. Huge. I think there may have been alligators living in it. The temporary tire forced us to decrease our average speed by 15 miles per hour. If the 39-mile drive usually takes us 45 minutes, how much time should we have budgeted for the drive home from the airport?

Want to read about something wild? Of course you do. Do a search for “Barkley Marathons.” This is a race so grueling that often nobody actually finishes. The race consists of five loops of 20 miles through the mountains of Tennessee. For those who make it to the last lap, the racers go in alternate directions around the course, which of course means they’ll meet in the middle somewhere. Let’s say that only two racers make it to the last lap, and it’s close: In fact, both start the last loop around the course at the same time. If one averages 2 miles per hour and the other 1.92 miles per hour, how many hours would it be until they meet? (Hint: Use a letter to represent the time until they meet. Then write expressions for the distance traveled by each racer. What do their distances have to add up to?)