Sara's mom takes the parkway to work. it takes her 30 minutes to travel from mile to maker 88 where she enters her exit mile maker 121. what is her average speed?

V = 66 mph

Explanation:

To calculate the speed, we need to use the following expression:

V = d/t

d: distance

t: time

Distance is in miles, while time is in seconds, however, we will convert this to hour for a better understanding.

30 minutes is half an hour or 0.5 h. This can be calculated also like this:

t = 30 min / 60 min/h = 0.5 h

Now, to get the distance travelled by Sara's mom, we just need to substract the marker 88 with the exit mile which is 121 so:

d = 121 - 88 = 33 mi

Finally, let's just replace distance and time in the first expression above:

V = 33/0.5

V = 66 mi/h

This is the average speed

the answer is c. nacl