Answer
Domain=[80, 100] ie. both of them inclusive.
Explanation:
Albert has total $105.
Let the cost of a product be c.
Therefore, the total cost of a product after the delivery and all is represented by a function f(c)
f(c)=c+
f(c)=
The domain, of the function is the no. of possible values of c that can satisfy the equation.
Now, lets check the maximum price of the product that Albert can buy.
f(c)=105
=105
c=$100
As, the minimum price of a product of is $80 , the domain needs to start from here. And it will go on till $100.
Domain=[80, 100]