Given:
Rita covered 1 mile in 15 minutes.
She covered 3 miles in 30 minutes.
To find:
The rate at which she is riding.
Solution:
Let y be the number of miles covered in x minutes.
Rita covered 1 mile in 15 minutes. So, the point is (15,1).
She covered 3 miles in 30 minutes. So, the point is (30,3).
Slope of the line:
[tex]m=\dfrac{y_2-y_1}{x_2-x_1}[/tex]
[tex]m=\dfrac{3-1}{30-15}[/tex]
[tex]m=\dfrac{2}{15}[/tex]
Therefore, she is riding [tex]\dfrac{2}{15}[/tex] miles per minute.