To solve this problem you must apply the proccedure shown below:
1. You have that Darren can get to work in [tex]30 minutes[/tex] and with the traffic and lights, he can average [tex]30 mph[/tex].Therefore, you must apply the formula for calculate the distance, which is:
[tex]d=Vt
[/tex]
Where [tex]V[/tex] is the speed and [tex]t
[/tex] is the time.
2. The time in hours is:
[tex]30 min=1/2 h
[/tex]
3. Substituying values, you have:
[tex]d=(30 mph)(1/2 h) \\ d=15 miles[/tex]
The answer is:[tex]15 miles[/tex]