हिंदी

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

Advertisements
Advertisements

प्रश्न

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
जोड़ियाँ मिलाइएँ
Advertisements

उत्तर

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

Explanation:

(a) We have to select 2 professor out of 10 and 3 lecturers out of 20

∴ Number of ways of selection = 10C2 × 20C

(b) When a particular professor is included taken the number of ways = `""^(10 – 1)"C"_1` × 20C3

= 9C1 × 20C3

(c) When a particular lecturer is included then number of ways = 10C2 × 19C2

(d) When a particular lecturer is excluded, then number of ways = 10C2 × 19C3 

shaalaa.com
  क्या इस प्रश्न या उत्तर में कोई त्रुटि है?
अध्याय 7: Permutations and Combinations - Exercise [पृष्ठ १२८]

APPEARS IN

एनसीईआरटी एक्झांप्लर Mathematics [English] Class 11
अध्याय 7 Permutations and Combinations
Exercise | Q 62 | पृष्ठ १२८

वीडियो ट्यूटोरियलVIEW ALL [1]

संबंधित प्रश्न

Determine the number of 5 card combinations out of a deck of 52 cards if there is exactly one ace in each combination.


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.


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?


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?


In a class there are 27 boys and 14 girls. The teacher wants to select 1 boy and 1 girl to represent the class in a function. In how many ways can the teacher make this selection?


There are 5 books on Mathematics and 6 books on Physics in a book shop. In how many ways can a students buy : (i) a Mathematics book and a Physics book (ii) either a Mathematics book or a Physics book?


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


How many different numbers of six digits can be formed from the digits 3, 1, 7, 0, 9, 5 when repetition of digits is not allowed?


If nC4 = nC6, find 12Cn.


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


How many different boat parties of 8, consisting of 5 boys and 3 girls, can be made from 25 boys and 10 girls?


In how many ways can a student choose 5 courses out of 9 courses if 2 courses are compulsory for every student?


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 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?


In how many ways can a student choose a programme of 5 courses if 9 courses are available and 2 specific courses are compulsory for every student?


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


Find the number of ways in which : (b) an arrangement, of four letters can be made from the letters of the word 'PROPORTION'.


Write \[\sum^m_{r = 0} \ ^{n + r}{}{C}_r\] in the simplified form.


If 20Cr = 20Cr + 4 , then rC3 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


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


The number of diagonals that can be drawn by joining the vertices of an octagon is


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


If n + 1C3 = 2 · nC2 , then n =


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


Find the value of 20C1619C16 


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 no girls


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 three girls.


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 ______.


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


A box contains 2 white balls, 3 black balls and 4 red balls. The number of ways three balls be drawn from the box if at least one black ball is to be included in the draw is ______.


To fill 12 vacancies there are 25 candidates of which 5 are from scheduled castes. If 3 of the vacancies are reserved for scheduled caste candidates while the rest are open to all, the number of ways in which the selection can be made is 5C3 × 20C9.


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 12 balls numbered from 1 to 12. The number of ways in which they can be used to fill 8 places in a row so that the balls are with numbers in ascending or descending order is equal to ______.


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 ______.


Share
Notifications

Englishहिंदीमराठी


      Forgot password?
Use app×