Permutations an...

In chess championship 153 games have been played. If a player with every other player plays only once, then the no. of players are _______

In a certain test there are n questions. In this test 2^k students gave wrong answers to at least n–k question. K = 0,1,2... n.If the no.of wrong answers is 4095 then value of n is _______

A class contain 4 boys and g girls every sunday 5 students including at least 3 boys go for a picnic to doll house, a different group being sent every week. during the picnic the class techer gives each girl in the group a doll . If the total no. of dolls distributed was 85, then value of g is _______

The no. of ways in which we can get a sum of the score of 11 by tossing three dices is _______

There are 3 set of parallel lines containing p lines, q lines and r lines resp. The greatest no. of parallelograms that can be formed by the system _______

If a polygon has 90 diagonals, the no. of its sides is given by _______