The motorcycle travels 40 miles in 60 minutes. To find this answer, you first simply the ratio 30 miles in 45 minutes (30:45). To simplify, divide both values by 15. This will give you 2 miles every 3 minutes.
Next, multiply 2:3 by 20, to show miles traveled after 60 minutes. Thus getting a final answer of 40 miles in 60 minutes. Here's an image to show how i solved this problem.
I hope this helps!