First figure your rate of travel which is figures in miles per hour. To do that you will need to change 90 minutes to hours. 90 minutes is 1 1/2 or 1.5 hours. Divide the miles (14.25) by 1.5. The answer is 9.5 miles per hour. If you go 9.5 miles in 1 hour, you will need to multiply the 9.5 miles by 2 hours to get the distance you can go in 2 hours. The answer is 19 miles.