Answer:
Average speed = 4 mph
Step-by-step explanation:
Given as
Total distance to travel = 6 mile
now, for first 2 mile the avg speed = 6 mph
for next 2 mile the avg speed = 4 mph
and for rest 2 mile the avg speed = 3 mph
so, the average speed of the Richard = [tex]\frac{3}{\frac{1}{6}+\frac{1}{4}+ \frac{1}{3} }[/tex]
Total Avg speed = [tex]\frac{3}{\frac{9}{12} }[/tex]
Or, = [tex]\frac{3}{9}[/tex]×12
= 4
So the total Average speed = 4 mph (Answer)