Michelle drove 50 miles per hour
Step-by-step explanation:
300 miles divided by 6 hours equals 50 miles per hour.
Miles per hour basically just means
You can infer from the use of the word 'per' that you should divide the number of miles by the number of hours to get an average speed.
Similarly, to work out the number of miles driven you could say you travelled 50 miles per hour for 6 hours, so you would multiply 50mph x 6 hours to work the equation in reverse.