If nP5 = 60.n - 1 P3 , then n is.
6
15
10
12
In how many different ways can the letters of the word 'DETAIL' be arranged in such a way that the vowels occupy only the odd positions?
32
48
36
60
How many 3-digit numbers can be formed from the digits 2, 3, 5, 6, 7 and 9, which are divisible by 5 and none of the digits is repeated?
5
20
In a group of 6 boys and 4 girls, four children are to be selected. In how many different ways can they be selected such that at least one boy should be there?
159
194
205
209
In how many different ways can the letters of the word 'CORPORATION' be arranged so that the vowels always come together?
810
1440
2880
50400
A box contains 2 white balls, 3 black balls and 4 red balls. In how many ways can 3 balls be drawn from the box, if at least one black ball is to be included in the draw?
64
96
In how many different ways can the letters of the word 'LEADING' be arranged in such a way that the vowels always come together?
360
480
720
5040
Twelve students compete for a race.The number of ways in which first three places can be taken as
3!
12.11.10
12!/3!
12! - 3
Ashok, Usha,Rani,Sonu are to give speeches in a class.The teacher can arrange the order of their presentation in
4 ways
12 ways
256 ways
24 ways
The number of different four digit numbers that can be formed with the digits 2,3,4,5,7 using each digit only once is.
4!
4 (4!)
5!
5 (7!)
