I will give u the steps
add up all of the values
then when you find the total lets say its 100% then total percent of cars would be 32%
The answer is 3. If you set it up in a T table and label x as the number of hours and y as the number of rows. Then use rise over run (y over x) the fractions simplify to 3 over 1.
7.35 in the answer which is what I had got in the calculator ;]