Welcome! You are encouraged to register with the site and login (for free). When you register, you support the site and your question history is saved.
Review: Driving at a Constant Rate
Explanation
Here we have a rate question, so we can set it up with a
fraction that includes the relevant units:
We want to get r miles
in the denominator without changing the value of the rate, so we can multiply
by a form of 1:
The s's in the
denominator cancel, leaving us with r miles.
The numerator becomes 
.
Therefore,
The correct answer is (A).
If you believe you have found an error in this question or explanation, please contact us and include the question title or URL in your message.