Question

julia rode a bicycle 6 miles in 30 minutes. alex rode his skateboard 2 miles in 12 minutes. who traveled at a greater average speed? define an appropriate unit of speed and provide mathematical justification for your answer.​

Answer 1

30 divided by 6 is 5 (so 5 min per mile)
12 divided by 2 is 6 (so 6 min per mile)
Therefore, Julia traveled at a greater speed

Answer 2

So Julia... 6 miles in 30 minutes. Let's find out how much she travelled in 1 hour. Multiply it by 2, since 30 x 2 = 60 mins = 1 hour, you get 12 miles per hour for Julia.

For Alex... 2 miles in 12 minutes. Multiply it by 5, as 12 x 5 = 60 mins = 1 hour, you get 10 miles per hour for Alex.

Julia travelled faster. She travelled 12 miles per hour while Alex travelled 10 miles per hour.