You can
put this solution on YOUR website! there are 3 airports. one flight flies from one airport to each of the other airports every day. how many flights are there in each day
Each flight has an AIRPORT OF DEPARTURE and an AIRPORT OF ARRIVAL. You can
choose the AIRPORT OF DEPARTURE in 3 ways and for everyone of those 3 ways,
there remain 2 ways to choose the AIRPORT OF ARRIVAL. That's 3×2 or 6 ways.
This is a permutation because ORDER MATTERS! The order of going FROM airport A
TO airport B is different from reversing the order and going from Airport B to
Airport A. ORDER MATTERS, so it's P(3,3) = 3! = 3×2×1 = 6. They are
1. Airport A to Airport B
2. Airport A to Airport C
3. Airport B to Airport A
4. Airport B to Airport C
5. Airport C to Airport A
6. Airport C to Airport B
Edwin
