Answer:
 represents the situation described below.
 represents the situation described below.
Step-by-step explanation:
A real-world situation could be
<em>Mary is runs everyday, she runs 15 kilometers per day, if she move at a constant speed, what would be the ratio that represents the time she needs everyday to make 15 kilometers.</em>
<em />
In this example, we have three quantities, distance traveled, speed and time. But, we already now the distance traveled, and we don't know the speed and time Mary uses to make 15 kilometer. We also know that the movement is constant, so it's defined by

Where  is speed,
 is speed,  is distance and
 is distance and  is time. So, if
 is time. So, if  , the ratio that represents time would be
, the ratio that represents time would be

Therefore, the algebraic expression that represents the hypothetical situation is 

Where  is time and
 is time and  is speed.
 is speed.