Answer to October 16, 2000 Problem

The Speeder's Problem

 
Two motorists travel from Winchester to Berryville, a distance of 15 miles. One travels at the legal speed limit of 55 mph while the other motorist travels at 75 mph.

If they both left Winchester at the same time, how much sooner would the law-breaking motorist arrive in Berryville?

 

Solution to Problem:

Answer is 4 minutes 22 seconds.

Solution:
A pet peeve of mine is the number of motorists who exceed the legal speed limit on the highway. I am convinced that if they would DO THE MATH, they would realize how little time they gain by speeding and thus slow down. In a 15 mile trip travelling 20 mph over the speed limit, only 4 minutes are gained!

The law-abiding motorist travels 15 miles at 55 mph, so it takes her .2727 hours or 16.36 minutes. The law-breaker travels the same 15 miles at 75 mph in a time of .2 hours or 12 minutes.

If a motorist were travelling at the prohibitive speed of 100 mph, it would take him .15 hours or 9 minutes, so he would save only 7 minutes!


Correctly solved by:

1. Liz Cotter Oak Hill, VA
2. Kirstine Wynn Winchester, VA
3. Tom Marino University of Richmond
4. Richard Mocarski Va. Tech
5. Chad McDaniel Winchester, VA
6. Erin McGinnis Winchester, VA
7. Ryan Throckmorton Winchester, VA
8. Jonathan O'Neill Winchester, VA
9. Becky Del Balzo Winchester, VA