Given data:
Each DVD's cost = $5
Sam has set aside total DVD's cost = $40
Sam can buy maximum DVD's = 40/5
= 8
Sam can buy minimum DVD's = 0
So, the domain for this situtaion is from 0 to 8.
The reasonable domain for the situtation is {x/ x belong to W, x is less than or equal to 8}
Here, W is the whole number.