Let us denote the set of all packages of pancake be P.
Then, [tex]P=[1, 2, 3}[/tex]
So, [tex]N(1)=90[/tex]
[tex]N(2)=90[/tex]
[tex]N(3)=90[/tex]
The function can be represented as [tex]N=[(1 ,90),(2 ,90),(3 ,90)][/tex]
Hence, domain = P and range = {90}