Permutation and Combination Questions

From 6 different novels and 3 different dictionaries, 4 novels and 1 dictionary are to be selected and arranged in a row on a shelf so that the dictionary is always in the middle. The number of such a...

Ten different letters of an alphabet are given. Words with five letters are formed from these given letters. Then, the number of words which have at least one letter repeated, is...

Number of divisors of the form (4n + 2), n ≥ 0 of the integer 240 is

The number of five digit numbers that can be formed using all the digits 0, 1, 3, 6, 8 which are -

A man saves Rs. 200 in each of the first three months of his service. In each of the subsequent months his saving increases by Rs. 40 more than the saving of immediately previous month. His total savi...

From 6 different novels and 3 different dictionaries, 4 novels and 1 dictionary are to be selected and arranged in a row on the shelf so that the dictionary is always in the middle. Then the number of...

If nCr denotes the number of combinations of n things taken r at a time, then the expression nCr + 1 + nCr-1 + 2 × nCr equals...

The letters of the word COCHIN are permuted and all the permutations are arranged in an alphabetical order as in an English dictionary. The number of words that appear before the word COCHIN is...

The number of ways in which n distinct objects can be put into two different boxes is-

The number of ways in which 3 persons can occupy 6 rooms separately is-

Find the total number of ways of answering 5 objective type questions, each question having 4 choices.

The number of ways in which first, second and third prize can be distributed among 5 competitors is (no person can get more than a prize)-

A lock consist of three rings each marked with 10 different digits. The number of unsuccessful attempts to open the lock is-

5 Questions are asked in a question paper. Out of which two questions can be solved by two- two methods, two question by three-three and one question can be solved by only one method then the number o...

In how many ways 4 paintings can be hung on 4 walls of a room so that (i) one painting is hung on each wall and (ii) any number of paintings can be hung on any wall?

In an examination, there are 3 multi-choice questions with one answer correct and each question has 4 alternatives. If a student is declared pass only when he attempts all questions correctly, then nu...

nCr + nCr−1 equals-

If 28C2r : 24C2 r-4 = 225:11 then the value of r is-

If nCn−4 = 5 then the value of n is -

There are 13 players of cricket out of which 4 are bowlers. In how many ways a team of eleven be selected from them so as to include at least two bowlers-