Question

Rita goes for a bike ride on a trail by her house. After 15 minutes of riding she sees a mile marker. When she reaches the third mile marker, she realizes that she has been biking for 30 minutes. What is the rate at which she is riding?

Answer 1

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:

$m=\dfrac{y_2-y_1}{x_2-x_1}$

$m=\dfrac{3-1}{30-15}$

$m=\dfrac{2}{15}$

Therefore, she is riding $\dfrac{2}{15}$ miles per minute.