SOLUTION: Your assistance with this would be greatly appreciated. I worked it out or at least I though I did, but my answer isn't on the list. "Two people leave their house at the same t

Question 11711: Your assistance with this would be greatly appreciated. I worked it out or at least I though I did, but my answer isn't on the list.
"Two people leave their house at the same time, A-rides north at 12mph, B-rides west at 5mph. Maintaining speed, how far apart after 2 hours of riding."
I had: D=RT, D=(12)(2)=24 and D=(5)(2)=10, then 24-10=14. But my choice for answers are: 34, 26, 17, 13 miles apart.

Answer by Earlsdon(6103) (Show Source):
You can put this solution on YOUR website!
You started out ok by finding the distance of the two riders from the starting point after two hours of travel. But, since these two are not traveling in a straight line, you cannot simply subtract their distances.
What you need to do is to draw a diagram showing one rider going north for 24 miles and the second rider going west for 10 miles. This forms the two legs of a right triangle. Their distance apart at this time is represented by the length of the hypotenuse of this right triangle, so you can use the Pythagorean theorem to calculate this length because you already know the lengths of the two legs.
c is the length of the hypotenuse or their distance apart after two hours of riding.

Take the square root of both sides.

They are 26 miles apart after two hours of riding.