Answer:
The number is [tex](S \ u \ C ) = 649[/tex]
Step-by-step explanation:
From the question we are told that
The sample size is n = 800
The number of seniors is S = 519
The number of commuters is C = 430
The number of of seniors that are commuters is [tex](S\ n \ C )= 300[/tex]
Generally the number of 800 surveyed students who were seniors or were commuters is mathematically evaluated as
[tex](S \ u \ C ) = S + C - ( S \ n \ C )[/tex]
=> [tex](S \ u \ C ) = 519 + 430 - 300[/tex]
=> [tex](S \ u \ C ) = 649[/tex]