If (n+2)! = 60(n-1)! find n.

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

A question paper has two parts A and B, each containing 10 questions. If a student has to choose 8 from part A, 5 from Part B, in how many ways can he choose the questions?

How many words (with or without dictionary meaning) can be made from the letters of the word MONDAY, assuming that no letter is repeated, if

	C1		C2
(a)	4 letters are used at a time	(i)	720
(b)	All letters are used at a time	(ii)	240
(c)	All letters are used but the first is a vowel	(iii)	360

Find n if ^{n - 1}P₃ : ⁿP₄ = 1 : 9