The value of n, when np2 = 20 is ________.
3
4
6
5
The number of different four digit numbers that canbe formed with the digits 2, 3, 4, 5, 7 using each digit only once is _______.
4 !
4 ( 4 ! )
5 !
5 ( 7 ! )
How many different arrangements can be made out of the letters in the expansion A2 B3 C4, when written in full ?
2! + 3! + 4!
2 ! 3!
None of these
How many 10 digits number can be written by using the digits 1 and 2.
10 C1 +9 C2
2 10
10C1
10 !
The number of distinct positive divisors of 22 32 53 is _______.
25
36
72
144
The number of selections of 2 candidate for a post out of 5 equally qualified candidates.
P ( 5, 2 )
( 5 - 2 ) !
10
P, Q, R, S are to give lectures to an audience. The organizer can arrange the order of their presentation in ______.
4 ways
12 ways
256 ways
24 ways
If npr = 720 ncr, then r is equal to _________.
7
Fifteen girls compete in a race. The first three places can be taken by them in ________.
3 ! ways
12! ways
15 x 14 x 13 ways
42 ways
The number of lines drawn through 6 points lying on a circle is ______
12
15
24
30
