Susan has 5 pounds of flour. She is purchasing more flour. She can purchase up to 5 bags of flour. Each bag weighs 20 pounds. Susan cannot purchase partial bags. The function that models the number of pounds of flour she has is f(b)=20b+5f(b)=20b+5 , where b is the number of bags of flour she purchases.

What is the practical domain of the function?

all real numbers

all integers from 1 to 5 inclusive

{25,45,65,85,105}{25,45,65,85,105}

all real numbers from 1 to 5 inclusive