Linux Scripting Problems

a) An executable file owned by root:root has the setuid bit set, it is run by jdoe:student. What effect does the setuid bit have in this case?

b) There is a directory that has a user owner of jdoe and a group owner of webdev with the setgid bit set. A user msmith with primary group msmith, who has write permissions on the directory, creates a new file in the directory. What are the user owner and group owner for the newly created file?