Answer:
Required ration which represent the situation = 
Step-by-step explanation:
Given: Cars in parking lot decreases at rate of 13 cars every 2 minutes.
To find: Rational Number which represent given information
Rational Number is a number in form of
where p be any integer and q is non zero integer.
So from given information
No of cars decreases in 2 minutes = 13 cars
So, No of cars decreases in 1 minute = 
Therefore rate at which cars decreasing in parking lot is
cars/min.
Since it is decreasing, ration which represent it must be equal to 
Therefore, Required ration which represent the situation = 