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 of these girls 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.

Answer 2

Nina's rate in miles per hour  is 12.71

The girl that bikes faster is Sophia.

Nina's rate in miles per hour is also known as Nina's average speed. Average speed is the total distance divided by total time travelled.  

Average speed = total distance / total time

In order to determine Nina's rate in miles per hour, feet has to be converted to miles and seconds would be converted to hour.

1 mile = 5280 feet

63,360 / 5280 = 12

1 hour = 3600 seconds

3400 / 3600 = 0.94 hours

Average speed = 12 / 0.94 = 12.71 miles / hour

In order to determine who bikes faster, the average speed of Sophia has to be determined.

Average speed = 10 / 1 = 10 miles per hour

Comparing the average speed, Sophia bikes faster.

To learn more about average speed, please check: brainly.com/question/9834403?referrer=searchResults