Answer:
Mrs Lunette can choose 816 combinations of 3 students.
Explanation:
We can use the combination formula to find the number of combinations Mrs Lunette has,
Number of combinations =

Where,
is the total number of students.
is how many students can be chosen at a time.
Now we can substitute the values to the above equation,
Number of combinations =

=

=

=

=

=

Mrs Lunette can choose 816 combinations of 3 students.