The sum of the digits in the unit place of all numbers formed with the help of 3,4,5,6 taken all at a time is
18
108
432
144
The total number of terms in the expansion of (x+y)100 + (x-y)100 after simplification is
202
100
50
51
How many 10 digit numbers can be written by suing digits 9 and 2
10c1 + 9c2
210
10c2
10!
The number of different permutations of the word 'BANANA' is
6
36
30
60
The total number of terms in the expansion of (x+y)100 +(x-y)100 after simplification is
The coefficient of xn in the expansion of (1+2x+3x2 +...) is
0
-1
1
2
The number of ways in which 5 boys and 5 girls can be seated for a photograph so that no two girls sit next to each other is
6!5!
(5!)2
, then r is
5
4
3
From 12 books, the difference between number of ways a selection of 5 books when one specified book is always excluded and one specified book is always included, is
64
118
132
330
9 balls are to be placed in 9 boxes and 5 of the balls cannot fit into 3 small boxes. The number of ways of arranging one ball in each of the boxes is
18720
18270
17280
12780
