# There are 3 letters and 3 addressed envelopes corresponding to them. The number of ways in which the letters be placed in the envelopes so that no letter is in the right envelope is

1.  5

2.  3

3.  1

4.  2

4

2

Explanation :
No Explanation available for this question

# The number of ways in which five different letters can be put in their five addressed envelopes so that all the letters are in the wrong envelopes is

1.  10

2.  30

3.  44

4.  17280

4

44

Explanation :
No Explanation available for this question

# The number of ways that all the letters of the word SWORD can be arranged such that no letter is in its original position is

1.  44

2.  32

3.  28

4.  20

4

44

Explanation :
No Explanation available for this question

# A is a set containing n elements. A subset P of A is chosen. The set A is reconstructed by replacing the elements of P. The subset Q of A is again chosen. The number of ways of choosing P and Q so that PQ= is

1.  2n

2.  2n+1

3.  2n-1

4.  22n

4

2n-1

Explanation :
No Explanation available for this question

# A set contains (2n+1) elements. The number of subsets of the set which contain most n elements is

1.  2n

2.  2n+1

3.  2n-1

4.  22n

4

22n

Explanation :
No Explanation available for this question

# A set contains (2n+1) elements. The number of subsets of the set which contain more than n elements is

1.  2n

2.  2n+1

3.  2n-1

4.  22n

4

22n

Explanation :
No Explanation available for this question

# A student is allowed to select atmost n books from a collection of (2n+1) books. If the total number of ways in which he can select books is 63, then n=

1.  4

2.  3

3.  7

4.  8

4

3

Explanation :
No Explanation available for this question

# A set contains (2n+1) elements. If the number of subsets of this set which contain atmost n elements is 4096, then the value of n is

1.  6

2.  15

3.   21

4.  none

4

6

Explanation :
No Explanation available for this question

# The number of ways of chosing n objects out of (3n+1) objects of which n are identical and (2n+1) are distinct, is

1.  22n

2.  22n+1

3.  22n-1

4.  none

4

22n

Explanation :
No Explanation available for this question

1.  44

2.  32

3.  28

4.  20

4