Answer:
30 mph
Explanation:
Average speed is calculated as
speed = [tex]\frac{distance}{time}[/tex] ( time must be in hours )
30 minutes = [tex]\frac{30}{60}[/tex] = [tex]\frac{1}{2}[/tex] hour , then
speed = [tex]\frac{15}{\frac{1}{2} }[/tex] = 15 × 2 = 30 miles per hour
