Question

One lap around a dirt track is 1/3 mile. It takes Bryce 1/9 hour to ride one lap. What is Bryce’s unite rate, in miles, around the track?

Answer 1

2 miles per hour

Explanation:

`color(blue)("Method")`

what we are looking for is miles in 1 hour mph
`->("miles")/("hour") -> "miles" -:"hours"`

So the unit of measurement of miles per hour is telling us that we divide the time into the distance.

Distance `-:` time `color(white)("d")->color(white)("d") 1/3" mile" -: 1/9" hours"color(white)("ddd") =color(white)("ddd") (1/3-:1/9) color(white)("d")("miles")/("hour")`

We have divided the numbers `(1/3-:1/9)` and we have divided the unites of measurement `("miles")/("hour")`
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
`color(blue)("The calculation")`

`1/3-:1/9color(white)("ddd") ->color(white)("ddd") 1/cancel(3)^1xxcancel(9)^2/1color(white)("d")=color(white)("d")2color(white)("d")("miles")/("hour")`