Shelly biked 21 miles in 4 hours. how long will it take shelly to bike 63 miles?

You can set up a proportion. So we see that shelly biked 21 miles in 4 hours. . Now you can cross multiply and get 21x (21 * x) = 252 (63*4). Then use the division property of equality and divide both sides by 21 to get x = 12 hours. Therefore Shelly biked 63 miles in 12 hours. Hope this helps! :D. Feel free to ask more questions, or ask questions about my explanation.

The correct answer is

21.14

:)