Question

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

Answer 1

You can set up a proportion. So we see that shelly biked 21 miles in 4 hours.
`(21)/(4) * (63)/(x)`. 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.

Answer 2

In order to do this, you need to use the equation:
distance=rate x time

So if you want to find out how long it will take you plug 63 miles into the equation.

63 miles=Rate x Time

You want to find out how long so you need the rate.

You can find the rate from the first sentence.

21miles=Rate X 4 hours
Rate=21/4 miles per hour
Plug this into the original equation.

63=(21/4)(time)

Time=12 hours