<h2>
Answer with explanation:</h2>
Part A:
- A relation is said to be a function where each input has only a single output.
We usually take the input variable as 'x' and the output variable as 'y'.
In the given table, we can see that 1 is the input value corresponding to 4 and 2 both.
i.e. one input value corresponds to two different output values that contradicts the definition of the function.
Thus the given table doesn't represent any function.
Part B: Given : The total cost f(x), in dollars, for renting a paddle-boat for x hours is shown below:

At x= 120 , 
It represents that the total cost for renting a paddle-boat for 120 hours is $1220.