हिंदी

F 24cx = 24c2x + 3, Find X. - Mathematics

Advertisements
Advertisements

प्रश्न

24Cx = 24C2x + 3, find x.

Advertisements

उत्तर

Given:
 24Cx = 24C2x + 3
We have,

\[24 = x + 2x + 3\] [∵\[{}^n C_x = {}^n C_y \Rightarrow x = y\]]  or, \[n = x + y\]
\[\Rightarrow 24 = 3x + 3\]
\[ \Rightarrow 3x = 21\]
\[ \Rightarrow x = 7\]
shaalaa.com
  क्या इस प्रश्न या उत्तर में कोई त्रुटि है?
अध्याय 17: Combinations - Exercise 17.1 [पृष्ठ ८]

APPEARS IN

आरडी शर्मा Mathematics [English] Class 11
अध्याय 17 Combinations
Exercise 17.1 | Q 5 | पृष्ठ ८

वीडियो ट्यूटोरियलVIEW ALL [1]

संबंधित प्रश्न

Determine n if  `""^(2n)C_3 : ""^nC_3 = 11: 1`


How many words, with or without meaning, can be formed using all the letters of the word EQUATION at a time so that the vowels and consonants occur together?


The English alphabet has 5 vowels and 21 consonants. How many words with two different vowels and 2 different consonants can be formed from the alphabet?


It is required to seat 5 men and 4 women in a row so that the women occupy the even places. How many such arrangements are possible?


Compute:

 L.C.M. (6!, 7!, 8!)


Prove that

\[\frac{1}{9!} + \frac{1}{10!} + \frac{1}{11!} = \frac{122}{11!}\]

How many four digit different numbers, greater than 5000 can be formed with the digits 1, 2, 5, 9, 0 when repetition of digits is not allowed?


If 15C3r = 15Cr + 3, find r.


If 28C2r : 24C2r − 4 = 225 : 11, find r.


If nC4 , nC5 and nC6 are in A.P., then find n.


If α = mC2, then find the value of αC2.


In how many ways can a football team of 11 players be selected from 16 players? How many of these will

 exclude 2 particular players?


A candidate is required to answer 7 questions out of 12 questions which are divided into two groups, each containing 6 questions. He is not permitted to attempt more than 5 questions from either group. In how many ways can he choose the 7 questions?


In how many ways can a committee of 5 persons be formed out of 6 men and 4 women when at least one woman has to be necessarily selected?


A group consists of 4 girls and 7 boys. In how many ways can a team of 5 members be selected if the team has (ii) at least one boy and one girl? 


A bag contains 5 black and 6 red balls. Determine the number of ways in which 2 black and 3 red balls can be selected.


In an examination, a question paper consists of 12 questions divided into two parts i.e., Part I and Part II, containing 5 and 7 questions, respectively. A student is required to attempt 8 questions in all, selecting at least 3 from each part. In how many ways can a student select the questions?


How many different words, each containing 2 vowels and 3 consonants can be formed with 5 vowels and 17 consonants?


If 20Cr = 20Cr + 4 , then rC3 is equal to


If mC1 nC2 , then


If nC12 = nC8 , then n =


If nCr + nCr + 1 = n + 1Cx , then x =


There are 10 points in a plane and 4 of them are collinear. The number of straight lines joining any two of them 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?


If C0 + C1 + C2 + ... + Cn = 256, then 2nC2 is equal to


Find the number of ways of drawing 9 balls from a bag that has 6 red balls, 5 green balls, and 7 blue balls so that 3 balls of every colour are drawn.


Ten students are to be selected for a project from a class of 30 students. There are 4 students who want to be together either in the project or not in the project. Find the number of possible selections.


Find the value of 20C1619C16 


If nCr – 1 = 36, nCr = 84 and nCr + 1 = 126, then find rC2.


A group consists of 4 girls and 7 boys. In how many ways can a team of 5 members be selected if the team has at least one boy and one girl


Everybody in a room shakes hands with everybody else. The total number of handshakes is 66. The total number of persons in the room is ______.


In a football championship, 153 matches were played, Every two teams played one match with each other. The number of teams, participating in the championship is ______.


The total number of ways in which six ‘+’ and four ‘–’ signs can be arranged in a line such that no two signs ‘–’ occur together is ______.


There are 3 books on Mathematics, 4 on Physics and 5 on English. How many different collections can be made such that each collection consists of:

C1 C2
(a) One book of each subject; (i) 3968
(b) At least one book of each subject: (ii) 60
(c) At least one book of English: (iii) 3255

There are 10 professors and 20 lecturers out of whom a committee of 2 professors and 3 lecturer is to be formed. Find:

C1 C2
(a) In how many ways committee: can be formed (i) 10C2 × 19C3 
(b) In how many ways a particular: professor is included (ii) 10C2 × 19C2
(c) In how many ways a particular: lecturer is included (iii) 9C1 × 20C3
(d) In how many ways a particular: lecturer is excluded (iv) 10C2 × 20C3

The number of positive integers satisfying the inequality `""^(n+1)C_(n-2) - ""^(n+1)C_(n-1) ≤ 100` is ______.


Total number of 6-digit numbers in which only and all the five digits 1, 3, 5, 7 and 9 appear is ______.


A regular polygon has 20 sides. The number of triangles that can be drawn by using the vertices but not using the sides is


Share
Notifications

Englishहिंदीमराठी


      Forgot password?
Use app×