Hey there! :)
Answer:
First part: 2 miles.
Second part: 45 minutes
Third part: 8 mph.
Step-by-step explanation:
We can divide this question into 3 parts.
Begin by solving for the distance traveled after 15 minutes by creating a ratio:
![\frac{20 mi}{150min} = \frac{x}{15 min}](https://tex.z-dn.net/?f=%5Cfrac%7B20%20mi%7D%7B150min%7D%20%20%3D%20%5Cfrac%7Bx%7D%7B15%20min%7D)
Cross multiply:
20 · 15 = 150 · x
300 = 150x
300/150 = 150x/150
x = 2 miles.
2nd part: How long it took her to ride 6 miles.
Set up another ratio similar to the one used before:
![\frac{20 mi}{150min} = \frac{6mi}{x min}](https://tex.z-dn.net/?f=%5Cfrac%7B20%20mi%7D%7B150min%7D%20%20%3D%20%5Cfrac%7B6mi%7D%7Bx%20min%7D)
Cross multiply:
20 · x = 6 · 150
20x = 900
20x/20 = 900/20
x = 45 minutes.
3rd part:
For this part, we will need to convert from minutes to hours.
![\frac{20 mi}{150 min}* \frac{60 min}{1 hr} = \frac{1200mi}{150hr} = 8 mi/h](https://tex.z-dn.net/?f=%5Cfrac%7B20%20mi%7D%7B150%20min%7D%2A%20%5Cfrac%7B60%20min%7D%7B1%20hr%7D%20%3D%20%5Cfrac%7B1200mi%7D%7B150hr%7D%20%20%20%3D%208%20mi%2Fh)
Therefore, her speed is 8 mph.