Frank rides his bike 10 mph faster than he walks. He can bike from home to work in the same amount of time that it takes him to walk from home to the park. If the distance from Frank's home to work is 6 miles and the distance from his home to the park is 2 miles, what is Frank's walking speed?
A) 7 mph
B) 6 mph
C) 6.5 mph
D) 5 mph

Question

Quizplus · Accepted Answer

Let's assume Frank's walking speed is x mph. Therefore, his biking speed would be (x+10) mph. Using the formula Distance = Speed x Time, we can set up two equations:
6 = (x+10)t      (time it takes for biking)
2 = xt               (time it takes for walking)
We can rearrange the second equation as t=2/x, and substitute it into the first equation:
6 = (x+10)(2/x)
6x = 2(x+10)
6x = 2x + 20
4x = 20
x = 5
Therefore, Frank's walking speed is 5 mph, which is answer choice D.

Frank Rides His Bike 10 Mph Faster Than He Walks