Permutations an...

A student is allowed to select at most n books from a collection of (2n + 1) books. If the total number of ways in which he can select one book is 63, then the value of n is

Out of 6 books, in how many ways can a set of one or more books be chosen

In the 13 cricket players 4 are bowlers, then how many ways can form a cricket team of 11 players in which at least 2 bowlers included

Six ‘+‘ and four ‘—‘ signs are to be placed in a straight line so that no two ‘—‘ signs come together, then the total number of ways are

In how many ways can 6 persons be selected from 4 officers and 8 constables, if at least one officer is to be

In an election there are 5 candidates and three vacancies. A voter can vote maximum to three candidates, then in how many ways can he vote

Out of 6 boys and 4 girls, a group of 7 is to be formed. In how many ways can this be done if the group is to have a majority of boys

The number of ways in which we can select three numbers from 1 to 3 so as to exclude every selection of all even numbers is

A man has 10 friends. In how many ways he can invite one or more of them to a party

The number of ways in which any four letters can be selected from the word \'CORGOO\' is