Question

A girl drove her bike at the rate of 10 moh and then after a flat tire she walked at the rate of 2 mph. The entire trip took 2 hours for a total of 16 miles. How long did she walk, and how long did she bike?

Answer 1

Let b be the biking time in hours

Let w be the walking time in hours

The entire trip took 2 hours


`b + w = 2`

for a total of 16 miles

If we've biked b hours at 10 miles per hour, then we must have biked 10b miles. Similarly for walking.


`10b + 2w = 16`


`2b + 2w = 4`

Subtracting,


`8b = 12`


`b = \frac 3 2` hours


`w = 2-b = \frac 1 2` hours

Biked 90 minutes, walked 30 minutes.