हिंदी

From 4 Officers and 8 Jawans in How Many Ways Can 6 Be Chosen (I) to Include Exactly One Officer

Advertisements
Advertisements

प्रश्न

From 4 officers and 8 jawans in how many ways can 6 be chosen (i) to include exactly one officer

Advertisements

उत्तर

From 4 officers and 8 jawans, 6 need to be chosen. Out of them, 1 is an officer.
Required number of ways =\[{}^4 C_1 \times {}^8 C_5 = 4 \times \frac{8!}{5! 3!} = 4 \times \frac{8 \times 7 \times 6 \times 5!}{5! \times 6} = 224\]

shaalaa.com
  क्या इस प्रश्न या उत्तर में कोई त्रुटि है?
अध्याय 17: Combinations - Exercise 17.2 [पृष्ठ १६]

APPEARS IN

आर.डी. शर्मा Mathematics [English] Class 11
अध्याय 17 Combinations
Exercise 17.2 | Q 9.1 | पृष्ठ १६

वीडियो ट्यूटोरियलVIEW ALL [1]

संबंधित प्रश्न

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?


Determine the number of 5-card combinations out of a deck of 52 cards if each selection of 5 cards has exactly one king.


Compute: 

(i)\[\frac{30!}{28!}\]


Compute:

 L.C.M. (6!, 7!, 8!)


Prove that

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

There are 6 multiple choice questions in an examination. How many sequences of answers are possible, if the first three questions have 4 choices each and the next three have 2 each?


How many three-digit numbers are there with no digit repeated?


Evaluate the following:

14C3


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


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 student is included.


How many different products can be obtained by multiplying two or more of the numbers 3, 5, 7, 11 (without repetition)?


How many different selections of 4 books can be made from 10 different books, if
there is no restriction;


How many different selections of 4 books can be made from 10 different books, if
two particular books are always selected;


How many different selections of 4 books can be made from 10 different books, if two particular books are never selected?


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


How many triangles can be obtained by joining 12 points, five of which are collinear?


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?


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 (i) no girl?


Find the number of (ii) triangles


Find the number of ways of selecting 9 balls from 6 red balls, 5 white balls and 5 blue balls if each selection consists of 3 balls of each colour.


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: atmost 3 girls?


Out of 18 points in a plane, no three are in the same straight line except five points which are collinear. How many (i) straight lines


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


Find the number of combinations and permutations of 4 letters taken from the word 'EXAMINATION'.


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


If 15C3r = 15Cr + 3 , then r is equal to


There are 12 points in a plane. The number of the straight lines joining any two of them when 3 of them are collinear, is


There are 3 wicketkeepers and 5 bowlers among 22 cricket players. A team of 11 players is to be selected so that there is exactly one wicketkeeper and at least 4 bowlers in the team. How many different teams can be formed?


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


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 selections be made?


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.


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 ______.


There are 12 points in a plane of which 5 points are collinear, then the number of lines obtained by joining these points in pairs is 12C25C2.


If some or all of n objects are taken at a time, the number of combinations is 2n – 1.


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 ______.


There are 12 persons seated in a line. Number of ways in which 3 persons can be selected such that atleast two of them are consecutive, is ______.


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


Share
Notifications

Englishहिंदीमराठी


      Forgot password?
Use app×