Derangements

IMPORTANT

Derangements: Overview

This topic covers concepts, such as, Arrangement of Words in the Form of Dictionary & Arrangement and Derangement in Permutation etc.

Important Questions on Derangements

EASY
IMPORTANT

In an examination, 5 students have been allotted their seats as per their roll numbers. The number of ways, in which none of the students sits on the allotted seat, is

EASY
IMPORTANT

5 boys with allotted roll numbers and seat numbers are seated in such a way that no one sits on the allotted seats. The number of ways of such seating arrangement is

HARD
IMPORTANT

Find the rank of the word MISSION if all words that can be formed using the letters are arranged in alphabetical order.

HARD
IMPORTANT

Find the rank of the word SUCCESS in the dictionary.

EASY
IMPORTANT

Number of ways in which 4 objects out of 6 distinct objects can be deranged are

MEDIUM
IMPORTANT

If the letters of the word PAPER are arranged in a dictionary, then the rank of the given word is

HARD
IMPORTANT

Let A=1,2,3,4,5,6,7. The number of surjective functions defined from A to A such that fi=i for atleast four values of i from i=1,2,......,7 , is

EASY
IMPORTANT

If all permutations of the letters of the word MASK are arranged in the order as m dictionary with or without meaning, which one of the following is 19th word?

MEDIUM
IMPORTANT

What is the rank of the word "BALL" in a dictionary that contains all permutation of the word "BALL" ?​

MEDIUM
IMPORTANT

Puneet writes letters to his five friends and address the corresponding envelopes. If λ be the numbers of total ways in which the letters can be placed in the envelopes so that at least three of them are in the wrong envelopes, then the value of λ100 is 

MEDIUM
IMPORTANT

The letters of the word "GOPAL" are permuted and all the permutations are arranged in an alphabetical order as in an English dictionary, then the rank of the word "GOPAL" is

HARD
IMPORTANT

10 people visit a temple. They leave their shoes outside the temple on returning from the temple on they wear the pair, assuming that each person wears both shoes of same pair. Find the number of ways in which exactly 5 person wear their own shoes.

HARD
IMPORTANT

If four letters are placed into 4 addressed envelopes at random, the probability that exactly two letters will go wrong is

HARD
IMPORTANT

If the letters of the word LATE be permuted and the words so formed be arranged as in a dictionary. Then the rank of LATE is -

HARD
IMPORTANT

A dictionary is printed consisting of 7 lettered words only that can be made with the letters of word CRICKET. If words are printed in the alphabetic order as in the dictionary then the number of words before the word CRICKET, is -

HARD
IMPORTANT

All the 7 digits numbers containing each of the 1,2,3,4,5,6,7 exactly once and not divisible by 5 are arranged in increasing order. Find 2015th number in this list?

MEDIUM
IMPORTANT

Let set A={x1,x2,x3,x4}and set  B={y1, y2, y3,y4}. If function is defined from set A to set B. Number of one-one function such that fxiyi for i=1,2,3,4  is equal to

MEDIUM
IMPORTANT

Number of ways by which 4 letters can be put in 4 corresponding envelopes so that all letters go in wrong envelope is

HARD
IMPORTANT

Seven people leave their bags outside a temple and after returning picked one bag each at random. In how many ways at least, one and atmost three of them get their correct bags?

HARD
IMPORTANT

If letters of the word "KUBER" are written in all possible orders and arranged as a dictionary, then rank of the word "KUBER" will be -