Shelly biked 21 miles in 4 hours. What is Shelly's average speed in miles per hour? At that same rate how many hours will it take Shelly to bike 42 miles?

5.25 mph, for 42 mile she would ride around 8 hours

Step-by-step explanation:

you need to divide the 21 miles by the 4 hours to find how many miles Shelly rode for one hour and that will be your answer (5.25 mph)

So, we need to do the distance she travelled (21 miles) divided by the rate at which she travelled (4 hours). Therefore, because 21 divided by 4 is 5.25, she biked at a speed of 5.25 mph (Miles per hour). So, if she bikes 5.25 miles every hour we can divide 42 by 5.25 to get the time it would take her to travel 42 miles. Now, 42 divided by 5.25 equals 8, so that means for Shelly to bike 42 miles at her average speed of 5.25 mph, it would take her 8 hours.