Question

A biker moves 2.5 times faster than a walker. They started moving simultaneously in the same direction from the same point. In two hours they were 18 miles apart. Find the biker's speeds.

Answer 1

15 mph

Explanation:

If the walker's speed is W, then the biker's speed is 2.5W. In 2 hours, the walker can travel 2W miles while the biker travels 5W. Since 5W-2W=18, 3W=18 and W=6. So the biker travels at a speed of 15 mph.

Answer 2

The speed of the biker is 15

Explanation:

First, you call the speed of the walker x, and the speed of the biker 2.5x.

Then you know that speed times time equals distance, so you set up and equation. You do x times 2, which is 2x, and then 2.5x times 2, which is 5x. Then, since the distance between them is 18 miles, the equation would be 5x-2x=18. You would get 3x=18, and x is 6. So 6 is the speed of the walker, and 6 times 2.5 = 15, so the speed of the biker is 15.