In how many ways can 10 examination papers be arranged so that the best and worst papers never come together?

In how many ways can 10 examination papers be arranged so that the best and the worst papers never come together?

In how many ways can 9 examination papers be arranged so that the best and the worst papers never come together?

In how many ways can 12 examination papers be arranged so that the best and the worst papers may never come together ?

In how many ways can 7 exmination paopers be arranged so that the best and the worst papers are never together?

The number of ways in which 8 examination papers be arranged so that the best and worst papers never come together is

In how many ways can five examination papers be arranged so that Physics and Chemistry papers never come together?

In how many ways can 9 examination papers arranged so the best and the worst papers are never together?

In how many ways can 9examination papers arranged so the best and the worst papers are never together?

In how many ways can 7 examination papers be arranged so that paper 1 and paper 2 never come toghether?