Question 1169186
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You can park in a a lot for 15$ an hour for at most 4 hours. A partial hour rounds to the nearest whole hour. 
find the function, domain and range. 
I thought the function was y=15x and the domain was all real numbers. 
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This post has a problem.


From the formal point of view, the cost function is not defined completely/properly in the post.


Namely,  for  EACH  of the values of  t= 0.5  hours,  1.5  hours,  2.5  hours and  3.5  hours,  there are 

TWO  closest integers,  and the post does not define properly/accurately,  which one of the two closest integer values to select.


So,  there is a  HUGE  HOLE  in the problem formulation, which remove the posted text from the class of correctly posed  Math problems.



If you will edit and re-post your problem,  I will show you the correct solution.


Notice that the answer by tutor  @Theo is not correct,  unfortunately.


The cost function in this problem is  DIFFERENT  from that shown in his post.