Honors problem 2

Question

Cindy rides a bicycle 12 miles per hour (mph) faster than Ned walks. Cindy completes a trail through the park on her bicycle in 15 minutes. Ned takes an hour to walk the trail.



How fast is Cindy moving?

Answer 1

Here distance travelled by both Cindy and Ned is same.

We know that distance = speed x time

 

Assume Ned walks at y (mph)

so, Cindy rides bicycle at y+12 (mph)

 

Since Cindy's speed is given in minutes, convert into hour by dividing it by 60

i.e 15minutes = 15/60 hours

 

speed of Ned is 1 hour

 

15/60(y+12) = 1y, since the distance covered by Ned and Cindy is the same

 

solving above equation we get y=4

 

Now the speed of Cindy is y+12 = 4+12 = 16 (mph)