Answer:
[tex]f(t)[/tex] is a function but not one-to-one.
Step-by-step explanation:
Please refer to my Answer from this Question to know how to Determine whether a Relation is a Function or not: brainly.com/question/24760829
This is a function because time can only move forward and there can't be different numbers of people, [tex]f(t)[/tex], at the same time, [tex]t[/tex]. The only thing that is possible is we can have the same number of people, [tex]f(t)[/tex], at the different times, [tex]t[/tex]. So, this isn't one-to-one but many-to-one.