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
How many 10 digits number can be written by using the digits 1 and 2.
10 C1 +9 C2
2 10
10C1
10 !
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
The number of lines drawn through 6 points lying on a circle is ______
12
15
24
30
If 4. 6pr = 6 pr + 1, then r is equal to ________.
4
3
2
1
The number of selections of 2 candidate for a post out of 5 equally qualified candidates.
P ( 5, 2 )
5 !
( 5 - 2 ) !
10
If nc2 = nc3 , then the value of nc4 is ________.
5
There are four letter boxes in a post office. In how many ways can a man post 8 distinct letters.
8 x 8
84
4 8
8 p 4
In an examination, a student has to answer 4 questons out of 6. questions 1 and 2 are however, compulsary. The number of ways in which the students can make the choice is _______.
C ( 6, 4 )
C ( 6, 2 )
6
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
