Answer:
The Answer is B
Step-by-step explanation:
Edgenuity ;)
Mario's unit rate is given by 900 miles/hour.
Explanation:
We have been given that Mario walked at a rate of 2/3 miles every 10 minutes.
We have the relation between speed, time and distance, which is given by

We have,
Distance = 
Time = 10 minutes
On substituting these values in the above formula, we get
\text{ miles/min}[/tex]
We have to find the unit rate in mile per hour, so we need to multiply it by 60
Thus, unit rate is given by

In this item, it is assumed that we are to determine the speed at which the car will have the best gas mileage. This can be done by deriving the equation and equating it to zero.
M(s) = -1/28s² + 3s - 31
Deriving,
dM(s) = (-1/28)(2s) + 3 = 0
s = 42
Hence, the speed at which the best mileage is achieved is mi/h.