Answer: 1.67 mph
Step-by-step explanation:
Given
Sam walk one-third of a mile in 12 minutes
There is 60 minutes in an hour i.e. Sam take
[tex]\Rightarrow t=\dfrac{12}{60}\\\\\Rightarrow t=0.2\ hr[/tex]
Average speed is given by
[tex]\Rightarrow v_{avg}=\dfrac{\text{distance}}{\text{time taken}}\\\\\Rightarrow v_{avg}=\dfrac{\frac{1}{3}}{0.2}\\\\\Rightarrow v_{avg}=\dfrac{5}{3}\ \text{or}\ 1.67\ mph[/tex]