Let b be the biking time in hours
Let w be the walking time in hours
The entire trip took 2 hours
[tex]b + w = 2[/tex]
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.
[tex]10b + 2w = 16[/tex]
[tex]2b + 2w = 4[/tex]
Subtracting,
[tex]8b = 12[/tex]
[tex]b = \frac 3 2 [/tex] hours
[tex]w = 2-b = \frac 1 2[/tex] hours
Biked 90 minutes, walked 30 minutes.
