Fundamental Principles of Counting

IMPORTANT

Fundamental Principles of Counting: Overview

This topic covers concepts such as Permutations and Combinations, Fundamental Principles of Counting (FPC), Addition Principle, Multiplication Principle, etc.

Important Questions on Fundamental Principles of Counting

EASY
IMPORTANT

Let   T n  denote the number of triangles which can be formed using the vertices of a regular polygon of  n sides. If  Tn+1Tn=21 , then  n equals

MEDIUM
IMPORTANT

An n-digit number is a positive number with exactly n digits. Nine hundred distinct n-digit numbers are to be formed using only the three digits 2, 5 and 7. The smallest value of n for which this is possible, is

HARD
IMPORTANT

The number of points, at which the two curves y=x99 and y=sinπx intersect, is

MEDIUM
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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

MEDIUM
IMPORTANT

4 buses runs between Bhopal and Gwalior. If a man goes from Gwalior to Bhopal by a bus and comes back to Gwalior by another bus, then the total possible ways are (bus can't take same path)

EASY
IMPORTANT

There are 5 roads leading to a town from a village. The number of different ways in which a villager can go to the town and return back, is

MEDIUM
IMPORTANT

Find the number of arrangements of the letters of the word ASSASSINATION.

EASY
IMPORTANT

In how many different ways can the letters of the word "LOGITECH" be arranged in such a way that the vowels always come together?

MEDIUM
IMPORTANT

Four couples (husband and wife) decide to form a committee of four members. The number of different committees that can be formed in which no couple finds a place is

EASY
IMPORTANT

Four normal dice are rolled once. The number of possible outcomes in which at least one die shows up 2 is -

MEDIUM
IMPORTANT

Find the number of arrangements of the letters of the word ASSASSINATION.

MEDIUM
IMPORTANT

Ajay refuses to sit next to either Bharat or Chandan. Deepak refuses to sit next to Enees. How many ways are there for the five of them to sit in a row of 5 chairs under these conditions ?

MEDIUM
IMPORTANT

Three of 128 objects are labeled A, B, C. You are told that A has rank 1, B has rank 2, and C has rank 3. Let the number of comparisons you need to check the given condition be N. Find the last two digits N.

HARD
IMPORTANT

In how many ways can a pack of 52 cards be divided equally into 4 groups? What is the number of ways if they are to be divided equally among 4 players?

HARD
IMPORTANT

Show that the total number of selections that can be made out of the letters of the phrase ‘daddy did a deadly deed’ is 1919.

HARD
IMPORTANT

Find the total number of selections taking at least one green ball and one blue ball, from 5 different green balls, 4 different blue balls and 3 different red balls.

HARD
IMPORTANT

In a group of 15 boys there are 7 boy-scouts. In how many ways can 12 boys be selected so as to include 

Exactly 6 boy-scouts, 

HARD
IMPORTANT

Find the number of proper divisors (including 1) of 3600.

MEDIUM
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A candidate has to secure the minimum marks in each of the 5 subjects to pass an examination. In how many ways can be fail?

MEDIUM
IMPORTANT

Find the number of different rectangles that are there on a chess board.