Part 1
What does it mean to say “correlation does not imply causation”?
The fact that two variables are strongly correlated implies a cause-and-effect relationship between the variables.
Two variables that have a cause-and-effect relationship are never correlated.
The fact that two variables are strongly correlated does not in itself imply a cause-and-effect relationship between the variables.
Your answer is correct.
Two variables can only be strongly correlated if there existed a cause-and-effect relationship between the variables.
Part 2
Which of the following pairs of variables have correlation, but no cause-and-effect relationship?
Number of school buses at a school and the number of students at a school
The number of students per teacher at a school and the number of teachers at a school
Number of school buses at a school and the number of teachers at a school
Your answer is correct.
The number of students per teacher at a school and the number of students at a school