Question

A plane flew 525 miles in 1.75 hours. Find the average speed of the plane.

Answer 1

We are trying to find the average speed of the plane, which is mph, or $\dfrac{\textrm{miles}}{\textrm{hour}}$. Using proportions, we can find the average speed of the plane in mph:

$\dfrac{525 \,\, \textrm{miles}}{1.75 \,\,\textrm{hours}} = \dfrac{x \,\, \textrm{miles}}{1 \,\,\textrm{hour}}$

• Use the information from the problem to create a proportion. Remember that we are looking for mph, so we will call that $x$.

$\dfrac{525}{1.75} \,\textrm{miles} = x \,\textrm{miles}$

• Multiply the entire equation by $1 \,\textrm{hour}$

$\dfrac{525}{1.75} = 300 = x$

• Divide both sides of the equation by $1 \,\textrm{mile}$ to clear both sides of the mile unit

The average speed of the plane is 300 mph.