English

Three balls are drawn from a bag containing 5 red, 4 white and 3 black balls. The number of ways in which this can be done if at least 2 are red is ______. - Mathematics

Advertisements
Advertisements

Question

Three balls are drawn from a bag containing 5 red, 4 white and 3 black balls. The number of ways in which this can be done if at least 2 are red is ______.

Fill in the Blanks
Advertisements

Solution

Three balls are drawn from a bag containing 5 red, 4 white and 3 black balls. The number of ways in which this can be done if at least 2 are red is 80.

Explanation:

We have 5 red, 4 white and 3 black balls out of which atleast 2 red balls are to be drawn

∴ Number of ways = 5C2 × 7C1 + 5C3

= 10 × 7 + 10

= 70 + 10

= 80

Hence, the value of the filler = 80.

shaalaa.com
  Is there an error in this question or solution?
Chapter 7: Permutations and Combinations - Exercise [Page 126]

APPEARS IN

NCERT Exemplar Mathematics [English] Class 11
Chapter 7 Permutations and Combinations
Exercise | Q 45 | Page 126

Video TutorialsVIEW ALL [1]

RELATED QUESTIONS

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


From among the 36 teachers in a college, one principal, one vice-principal and the teacher-incharge are to be appointed. In how many ways can this be done?


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


How many three-digit numbers are there?


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 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?


A number lock on a suitcase has 3 wheels each labelled with ten digits 0 to 9. If opening of the lock is a particular sequence of three digits with no repeats, how many such sequences will be possible? Also, find the number of unsuccessful attempts to open the lock.


Evaluate the following:

14C3


If 15C3r = 15Cr + 3, find r.


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


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?


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?


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?


In how many ways can a team of 3 boys and 3 girls be selected from 5 boys and 4 girls?


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?


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?


Find the number of ways in which : (a) a selection


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


There are 3 letters and 3 directed envelopes. Write the number of ways in which no letter is put in the correct envelope.


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


Given 11 points, of which 5 lie on one circle, other than these 5, no 4 lie on one circle. Then the number of circles that can be drawn so that each contains at least 3 of the given points 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.


There are 8 doctors and 4 lawyers in a panel. Find the number of ways for selecting a team of 6 if at least one doctor must be in the team.


Find the value of 20C1619C16 


Answer the following:

A question paper has 6 questions. How many ways does a student have to answer if he wants to solve at least one question?


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


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?


A bag contains six white marbles and five red marbles. Find the number of ways in which four marbles can be drawn from the bag if two must be white and two red


A bag contains six white marbles and five red marbles. Find the number of ways in which four marbles can be drawn from the bag if they must all be of the same colour.


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


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


15C8 + 15C915C615C7 = ______.


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.


Number of selections of at least one letter from the letters of MATHEMATICS, is ______.


Share
Notifications

Englishहिंदीमराठी


      Forgot password?
Use app×