Question

Nina can ride her bike 63,360 feet in 3,400 seconds, and Sophia can ride her bike 10 miles in 1 hour. What is Nina's rate in miles per hour if there are 5,280 feet in a mile? Which girl bikes faster?

Answer 1

We know that 
3600 seconds = 1 hour

Then

3400 seconds = 3400/3600

                        = 17/18 hours

5280 feet = 1 mile

Then
63360 feet = 63360/5280 mile

                  = 12 mile

So
Distance covered by Nina in 17/18 hours = 12 mile

Then

Distance covered by Nina in 1 hour = 12/(17/18) miles

                                                         = 12.71 miles.

From the above deduction, we can conclude that the speed of Nina is 12.71 miles per hour.

Speed of Sophia is 10 miles per hour. So Nina is the girl that rides at a faster speed.
______________________________
If you find my answer helpful mark it as brainliest