Answer to March 5, 2001 Problem of the Week

When you travel to work going 60 mph, you arrive there early.

When you travel to work going 30 mph, you arrive there late.

The amount of time you are early is also the amount of time you are late.

How fast should you go to get to work exactly on time?

Solution to the Problem:

You should travel at 40 mph.

Let x = distance to work (in miles).

	Rate	Time	Distance
Early	60 mph	x/60 hr	x miles
Late	30 mph	x/30 hr	x miles
On Time	40 mph	x/40 hr	x miles

You should average the two times x/60 and x/30 since the amount of time you arrive early equals the amount of time you arrive late.
(x/60 + x/30) / 2 = x/40

If you travel x miles in x/40 hours, you must travel at 40 mph.

Correctly solved by:

1. David Dixon	Bennettsville, South Carolina
2. Rich Murray	Ridgetown, Ontario
3. Walt Arrison	Philadelphia, Pennsylvania
4. Sasha Joseph	Hebron, Maine
5. Ryan Charest	Winchester, Virginia
6. Ricki Stern	Highland Park, New Jersey
7. Keith Mealy	Cincinnati, Ohio
8. Kasturi Rajendran	----------
9. Steve Stermer	Colorado Springs, Colorado
10. Izzy Kushner	Closter, New Jersey
11. Erin McGinnis	Winchester, Virginia
12. Evelyne Stalzer	New Jersey
13. Kirstine Wynn	Winchester, Virginia
14. David Powell	Winchester, Virginia
15. Jim Kennedy	Limerick, Ireland (via Holland)
16. Bill Hall	Wellington, Florida
17. Geoff Keith	Santa Monica, California
18. Richard Johnson	La Jolla, California

March 5, 2001 Problem of the Month

Correctly solved by:

March 5, 2001
Problem of the Month