मराठी

If 18cx = 18cx + 2, Find X.

Advertisements
Advertisements

प्रश्न

If 18Cx = 18Cx + 2, find x.

Advertisements

उत्तर

Given: 
18Cx = 18Cx + 2

By using

\[{}^n C_x = {}^n C_y \Rightarrow x = y\] or \[n = x + y\]
 we get,
\[18 = x + x + 2\]
\[ \Rightarrow 2x = 16\]
\[ \Rightarrow x = 8\]
shaalaa.com
  या प्रश्नात किंवा उत्तरात काही त्रुटी आहे का?
पाठ 17: Combinations - Exercise 17.1 [पृष्ठ ८]

APPEARS IN

आर.डी. शर्मा Mathematics [English] Class 11
पाठ 17 Combinations
Exercise 17.1 | Q 6 | पृष्ठ ८

व्हिडिओ ट्यूटोरियलVIEW ALL [1]

संबंधित प्रश्‍न

Determine n if  `""^(2n)C_3 : ""^nC_3 = 12 : 1`


How many 6-digit numbers can be formed from the digits 0, 1, 3, 5, 7 and 9 which are divisible by 10 and no digit is repeated?


From Goa to Bombay there are two roots; air, and sea. From Bombay to Delhi there are three routes; air, rail and road. From Goa to Delhi via Bombay, how many kinds of routes are there?


A team consists of 6 boys and 4 girls and other has 5 boys and 3 girls. How many single matches can be arranged between the two teams when a boy plays against a boy and a girl plays against a girl?


How many three-digit numbers are there?


How many different five-digit number licence plates can be made if

first digit cannot be zero and the repetition of digits is not allowed,


How many different five-digit number licence plates can be made if

the first-digit cannot be zero, but the repetition of digits is allowed?


How many four-digit numbers can be formed with the digits 3, 5, 7, 8, 9 which are greater than 7000, if repetition of digits is not allowed?


In how many ways can six persons be seated in a row?


How many 9-digit numbers of different digits can be formed?


How many odd numbers less than 1000 can be formed by using the digits 0, 3, 5, 7 when repetition of digits is not allowed?


How many 3-digit numbers are there, with distinct digits, with each digit odd?


There are 10 professors and 20 students out of whom a committee of 2 professors and 3 students is to be formed. Find the number of ways in which this can be done. Further find in how many of these committees:
a particular professor is included.


From 4 officers and 8 jawans in how many ways can 6 be chosen. to include at least one officer?


We wish to select 6 persons from 8, but if the person A is chosen, then B must be chosen. In how many ways can the selection be made?


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.


A committee of 7 has to be formed from 9 boys and 4 girls. In how many ways can this be done when the committee consists of: at least 3 girls?


If 20Cr = 20Cr−10, then 18Cr is equal to


If nCr + nCr + 1 = n + 1Cx , then x =


If\[\ ^{( a^2 - a)}{}{C}_2 = \ ^{( a^2 - a)}{}{C}_4\] , then a =


The number of ways in which a host lady can invite for a party of 8 out of 12 people of whom two do not want to attend the party together is


Among 14 players, 5 are bowlers. In how many ways a team of 11 may be formed with at least 4 bowlers?


Find n and r if `""^"n""P"_"r"` = 720 and `""^"n""C"_("n" - "r")` = 120


There are 20 straight lines in a plane so that no two lines are parallel and no three lines are concurrent. Determine the number of points of intersection.


Five students are selected from 11. How many ways can these students be selected if two specified students are not selected?


Find the value of 80C2


In how many ways can the letters of the word 'IMAGE' be arranged so that the vowels should always occupy odd places?


A student has to answer 10 questions, choosing atleast 4 from each of Parts A and B. If there are 6 questions in Part A and 7 in Part B, in how many ways can the student choose 10 questions?


In how many ways a committee consisting of 3 men and 2 women, can be chosen from 7 men and 5 women?


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 from the lot.


There are 10 lamps in a hall. Each one of them can be switched on independently. Find the number of ways in which the hall can be illuminated.


In an examination, a student has to answer 4 questions out of 5 questions; questions 1 and 2 are however compulsory. Determine the number of ways in which the student can make the choice.


A convex polygon has 44 diagonals. Find the number of its sides.


In how many ways can a football team of 11 players be selected from 16 players? How many of them will exclude 2 particular players?


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


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. He can choose the seven questions in 650 ways.


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

A badminton club has 10 couples as members. They meet to organise a mixed double match. If each wife refers to p artner as well as oppose her husband in the match, then the number of different ways can the match off will be ______.


Share
Notifications

Englishहिंदीमराठी


      Forgot password?
Use app×