Question

Mario walked at a rate of mile every minutes.
​What was his walking rate in miles per hour?

Answer 1

Answer: 4mi/h

Explanation:

We have that Mario walks 2/3 of a mile every 10 minutes. Representing this as a fraction:

`(2/3)/(10) (mile)/(minute)`

Next, you can use something called "dimensional analysis." A dimenision in this case would be the units. The desired units we want are miles per hour, but we are given miles per minute. You can use a few conversion factors to help get to those desired units. In 60 minutes, there is 1 hour. Let's multiply this conversion factor by our original fraction:

`(2/3)/(10) (miles)/(minute)*(60)/(1) (minute)/(hour)`

As you can see above, the units of minutes will cancel. This will leave the units of miles on top, and hours on the bottom. Our units are now miles per hour after simplifying things:

`(2/3)/(10)(60)/(1) (miles)/(hour)=2/3*6 (miles)/(hour)=4(miles)/(hour)`