हिंदी

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 ______.

Advertisements
Advertisements

प्रश्न

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 ______.

रिक्त स्थान भरें
Advertisements

उत्तर

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 18.

Explanation:

Let the number of participating teams be n

Given that every two teams played one match with each other.

∴ Total number of matches played = nC2

So nC2 = 153

⇒ `(n(n - 1))/2` = 153

⇒ n2 – n = 306

⇒ n2 – n – 306 = 0

⇒ n2 – 18n + 17n – 306 = 0

⇒ n(n – 18) + 17(n – 18) = 0

⇒ (n – 18)(n + 17) = 0

⇒ n – 18 = 0 and n + 17 = 0

⇒ n = 18, n ≠ – 17

Hence, the value of the filler is 18.

shaalaa.com
  क्या इस प्रश्न या उत्तर में कोई त्रुटि है?
अध्याय 7: Permutations and Combinations - Exercise [पृष्ठ १२६]

APPEARS IN

एनसीईआरटी एक्झांप्लर Mathematics Exemplar [English] Class 11
अध्याय 7 Permutations and Combinations
Exercise | Q 47 | पृष्ठ १२६

वीडियो ट्यूटोरियलVIEW ALL [1]

संबंधित प्रश्न

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?


From a class of 25 students, 10 are to be chosen for an excursion party. There are 3 students who decide that either all of them will join or none of them will join. In how many ways can the excursion party be chosen?


Compute:

 L.C.M. (6!, 7!, 8!)


A coin is tossed five times and outcomes are recorded. How many possible outcomes are there?


Given 7 flags of different colours, how many different signals can be generated if a signal requires the use of two flags, one below the other?


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?


Since the  number has to be greater than 8000, the thousand's place can be filled by only two digits, i.e. 8 and 9.
Now, the hundred's place can be filled with the remaining 4 digits as the repetition of the digits is not allowed.
The ten's place can be filled with the remaining 3 digits.
The unit's place can be filled with the remaining 2 digits.
Total numbers that can be formed = `2xx4xx3xx2=48`


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


How many different numbers of six digits each can be formed from the digits 4, 5, 6, 7, 8, 9 when repetition of digits is not allowed?


If nC10 = nC12, find 23Cn.


If 15Cr : 15Cr − 1 = 11 : 5, find r.


If n +2C8 : n − 2P4 = 57 : 16, find n.


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


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

include 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?


Find the number of diagonals of , 1.a hexagon


Find the number of diagonals of (ii) a polygon of 16 sides.


In a village, there are 87 families of which 52 families have at most 2 children. In a rural development programme, 20 families are to be helped chosen for assistance, of which at least 18 families must have at most 2 children. In how many ways can the choice be made?


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(iii) at least 3 girls? 


Determine the number of 5 cards combinations out of a deck of 52 cards if at least one of the 5 cards has to be a king?


In how many ways can one select a cricket team of eleven from 17 players in which only 5 persons can bowl if each cricket team of 11 must include exactly 4 bowlers?


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: exactly 3 girls?


If nCr + nCr + 1 = n + 1Cx , then x =


In how many ways can a committee of 5 be made out of 6 men and 4 women containing at least one women?


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?


The value of\[\left( \ ^{7}{}{C}_0 + \ ^{7}{}{C}_1 \right) + \left( \ ^{7}{}{C}_1 + \ ^{7}{}{C}_2 \right) + . . . + \left( \ ^{7}{}{C}_6 + \ ^{7}{}{C}_7 \right)\] is


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


The value of `(""^9"C"_0 + ""^9"C"_1) + (""^9"C"_1 + ""^9"C"_2) + ... + (""^9"C"_8 + ""^9"C"_9)` is ______ 


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


A box contains two white, three black and four red balls. In how many ways can three balls be drawn from the box, if atleast one black ball is to be included in the draw


The number of triangles that are formed by choosing the vertices from a set of 12 points, seven of which lie on the same line is ______.


The number of parallelograms that can be formed from a set of four parallel lines intersecting another set of three parallel lines is ______.


The number of ways in which we can choose a committee from four men and six women so that the committee includes at least two men and exactly twice as many women as men is ______.


A committee of 6 is to be chosen from 10 men and 7 women so as to contain atleast 3 men and 2 women. In how many different ways can this be done if two particular women refuse to serve on the same committee ______.


All possible numbers are formed using the digits 1, 1, 2, 2, 2, 2, 3, 4, 4 taken all at a time. The number of such numbers in which the odd digits occupy even places is ______.


The no. of different ways, the letters of the word KUMARI can be placed in the 8 boxes of the given figure so that no row remains empty will be ______.


Share
Notifications

Englishहिंदीमराठी


      Forgot password?
Use app×