Question

Set A contains zip codes from the US and set B contains US citizen's social security numbers. The elements
of these sets can be paired in that each person has a zip code for their legal address (or domicile) and each
person has a social security number.
(a) If these are written as ordered pairs of the form
(zip code; Social security number)
do we have a function? Why or why not?
(b) If these are written as ordered pairs of the form
(Social security number; zip code)
do we have a function? Why or why not?
Hint: Every US citizen has exactly one legal address even if they own more than o