Explanation:

Given, the total number of teachers in a school = 36
To find: The number of ways in which one principal and one vice-principal can be appointed
Formula used:
Number of arrangements of n things taken r at a time = P(n, r)
∴ The total number of ways in which this can be done
= the number of arrangements of 36 things taken 2 at a time
= 36!/(36-2)!
=36!/34!
= P(36, 2)
= 36 × 35
= 1260
Hence, Number of ways in which one principal and one vice-principal are to be appointed out of total 36 teachers in school are 1260