Question

The distance from Phoenix to Tucson is 120 miles. A car made the journey in 1 hour and 45 minutes. What was the average speed of the car in miles per hour?

A marathon is a race of 26.2 miles. Wilson Kipsang set a new world record time of approximately 2 hours and 3 minutes. What was his average speed in mile per hour?

Answer 1

Speed of a car is distance/time.
The distance is 120 miles.
The time is 1 hour 45 minutes.

Same idea for the second problem.

Answer 2

everyone keeps telling me that but ive no idea how to actually plug that in or how to do it

Answer 3

distance is 120 miles, let's call it d
time is 1 hr, 45 mins or 1.75 hrs, let's call that t
speed is unknown here, let's call that s

So the basic equation is \[speed = \frac{ distance }{ time }\]
or \[s=\frac{ d }{ t }\]
so, \[s=\frac{ 120 }{ 1.75 }\]
\[s=68.6\]
Now to check to make sure it makes sense, how far would I go if I drove 68.6 miles per hour for 1.75 hours?
\[68.6\times1.75=120\]
and you'll notice if you use your calculator that there's some rounding error with respect to that 120.
Try to use the same setup to solve for the unknown in your marathon question.