Advertisements
Advertisements
प्रश्न
Five students are selected from 11. How many ways can these students be selected if two specified students are not selected?
Advertisements
उत्तर
Number of students is 11. We have to select 5 students
2 particular students are not selected:
If 2 particular students are not selected, then from remaining (11 – 2) = 9 students, we have to select 5 students.
This can be done in 9C5 ways.
∴ total number of selections
= 9C5
= `9/(5!4!)`
= `(9 xx 8 xx 7 xx 6)/(1 xx 2 xx 3 xx 4)`
= 126.
APPEARS IN
संबंधित प्रश्न
Find the value of `""^20"C"_16 - ""^19"C"_16`
Find r if `""^14"C"_(2"r"): ""^10"C"_(2"r" - 4)` = 143:10
Find n and r if `""^"n""C"_("r" - 1): ""^"n""C"_"r": ""^"n""C"_("r" + 1)` = 20:35:42
If `""^"n""P"_"r" = 1814400` and `""^"n""C"_"r"` = 45, find r.
If `""^"n""C"_("r" - 1)` = 6435, `""^"n""C"_"r"` = 5005, `""^"n""C"_("r" + 1)` = 3003, find `""^"r""C"_5`.
Find the number of ways of selecting a team of 3 boys and 2 girls from 6 boys and 4 girls.
Find the number of diagonals of an n-shaded polygon. In particular, find the number of diagonals when: n = 12
Ten points are plotted on a plane. Find the number of straight lines obtained by joining these points if four points are collinear.
Find the number of triangles formed by joining 12 points if no three points are collinear,
Find the number of triangles formed by joining 12 points if four points are collinear.
A word has 8 consonants and 3 vowels. How many distinct words can be formed if 4 consonants and 12 vowels are chosen?
Find n, if `""^(2"n")"C"_("r" - 1) = ""^(2"n")"C"_("r" + 1)`
Find r if `""^11"C"_4 + ""^11"C"_5 + ""^12"C"_6 + ""^13"C"_7 = ""^14"C"_"r"`
Find the differences between the largest values in the following: `""^13"C"_r "and" ""^8"C"_r`
Find the differences between the largest values in the following: `""^15"C"_r "and" ""^11"C"_r`
A question paper has two sections. section I has 5 questions and section II has 6 questions. A student must answer at least two questions from each section among 6 questions he answers. How many different choices does the student have in choosing questions?
Nine friends decide to go for a picnic in two groups. One group decides to go by car and the other group decides to go by train. Find the number of different ways of doing so if there must be at least 3 friends in each group.
If nPr = 1814400 and nCr = 45, find n+4Cr+3
If nCr–1 = 6435, nCr = 5005, nCr+1 = 3003, find rC5
Find the number of ways of selecting a team of 3 boys and 2 girls from 6 boys and 4 girls
After a meeting, every participant shakes hands with every other participants. If the number of handshakes is 66, find the number of participants in the meeting.
Find the number of diagonals of an n-sided polygon. In particular, find the number of diagonals when n = 12
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
Ten points are plotted on a plane. Find the number of straight lines obtained by joining these points if four points are collinear
Find the differences between the greatest values in the following:
15Cr and 11Cr
A group consists of 9 men and 6 women. A team of 6 is to be selected. How many of possible selections will have at least 3 women?
A committee of 10 persons is to be formed from a group of 10 women and 8 men. How many possible committees will have at least 5 women? How many possible committees will have men in majority?
Five students are selected from 11. How many ways can these students be selected if two specified students are selected?
Answer the following:
Ten students are to be selected for a project from a class of 30 students. There are 4 students who want to be together either in the project or not in the project. Find the number of possible selections
Answer the following:
Nine friends decide to go for a picnic in two groups. One group decides to go by car and the other group decides to go by train. Find the number of different ways of doing so if there must be at least 3 friends in each group.
Answer the following:
Find the number of ways of dividing 20 objects in three groups of sizes 8, 7 and 5
Answer the following:
There are 4 doctors and 8 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
The maximum value of z = 9x + 11y subject to 3x + 2y ≤ 12, 2x + 3y ≤ 12, x ≥ 0, y ≥ 0 is _______.
What is the probability of getting a “FULL HOUSE” in five cards drawn in a poker game from a standard pack of 52-cards?
[A FULL HOUSE consists of 3 cards of the same kind (eg, 3 Kings) and 2 cards of another kind (eg, 2 Aces)]
Out of 7 consonants and 4 vowels, the number of words (not necessarily meaningful) that can be made, each consisting of 3 consonants and 2 vowels, is ______.
