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
`\frac{\textrm{miles}}{\textrm{hour}}`. Using proportions, we can find the average speed of the plane in mph:

`\frac{525 \,\, \textrm{miles}}{1.75 \,\,\textrm{hours}} = \frac{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`.

`(525)/(1.75) \,\textrm{miles} = x \,\textrm{miles}`

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

`(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.