Permutations an...

Nandan gives dinner party to six guests.the no of ways in which they may be selected from ten friends if two of the friends will not attend the party together is: _______

The no, of straight lines that can be drawn out of 10 points of which 7 are collinear is _______

The no of ways of arranging the letters AAAAABBBCCCDEEF in a row when no two c’s are together is: _______

The no of ways in which 10 persons can go in two cars so that there may be 5 in each car, supposing that two particular persons will not go in the same car is:

The number of ways of distributing 8 identical balls in 3 distinct boxes so that none of the boxes is empty are: _______

There are 10 points in a plane out of these 6 are collinear. If N is the number of triangles formed by joining these points then:

There are 3 copies each of 4 different books.The number of ways they can be arranged in a shelf is _______

The number of ways in which 5 identical balls can be kept in 10 identical boxes. If not more than one can go in to a box is _______

The vertices of a regular polygon of 12 sides are joined to form triangles.The no. of triangles which do not have their sides as the sides of the polygon is _______