Advertisements
Advertisements
प्रश्न
Find the total number of subsets of a set with
[Hint: nC0 + nC1 + nC2 + ... + nCn = 2n] 5 elements
उत्तर
Subsets with 5 elements:
Number of subsets with no element = 5C0
Number of subsets with one element = 5C1
Number of subsets with 2 elements = 5 C2
Number of subsets with 3 elements = 5C3
Number of subjects with 4 elements = 5C4
Number of subsets with 5 elements = 5C5
Total number of subjects
= 5C0 + 5C1 + 5C2 + 5C3 + 5C4 + 5C5
= `1 + (5!)/(1!(5 - 1)!) + (5!)/(2!(5 - 2)!) + (5!)/(3!(5 - 3)!) + (5!)/(4!(5 - 4)!) + 1`
= `1 + (5!)/(4!) + (5!)/(2! 3!) + (5!)/(3! 2!) + (5!)/(4!) + 1`
= `1 + (5 xx 4!)/(4!) + (5 xx 4 xx 3!)/(2! xx 3!) + (5 xx 4 xx 3!)/(3! xx 2!) + (5 xx 4!)/(4!) + 1`
= `1 + 5 + (5 xx 4)/(2 xx 1) + (5 xx 4)/(2 xx 1) + 5 + 1`
= 6 + 10 + 10 + 6
= 32
APPEARS IN
संबंधित प्रश्न
How many triangles can be formed by joining the vertices of a hexagon?
In how many ways can a cricket team of 11 players be chosen out of a batch of 15 players?
- There is no restriction on the selection.
- A particular player is always chosen.
- A particular player is never chosen.
If nC3 = nC2 then the value of nC4 is:
The value of n, when np2 = 20 is:
If nPr = 720(nCr), then r is equal to:
The number of diagonals in a polygon of n sides is equal to
The value of (5C0 + 5C1) + (5C1 + 5C2) + (5C2 + 5C3) + (5C3 + 5C4) + (5C4 + 5C5) is:
A Kabaddi coach has 14 players ready to play. How many different teams of 7 players could the coach put on the court?
There are 15 persons in a party and if each 2 of them shakes hands with each other, how many handshakes happen in the party?
Find the total number of subsets of a set with
[Hint: nC0 + nC1 + nC2 + ... + nCn = 2n] n elements
How many different selections of 5 books can be made from 12 different books if, Two particular books are always selected?
A committee of 7 peoples has to be formed from 8 men and 4 women. In how many ways can this be done when the committee consists of exactly 3 women?
7 relatives of a man comprises 4 ladies and 3 gentlemen, his wife also has 7 relatives; 3 of them are ladies and 4 gentlemen. In how many ways can they invite a dinner party of 3 ladies and 3 gentlemen so that there are 3 of man’s relative and 3 of the wife’ s relatives?
A box contains two white balls, three black balls and four red balls. In how many ways can three balls be drawn from the box, if at least one black ball is to be included in the draw?
How many triangles can be formed by joining 15 points on the plane, in which no line joining any three points?
A polygon has 90 diagonals. Find the number of its sides?
Choose the correct alternative:
`""^(("n" - 1))"C"_"r" + ""^(("n" - 1))"C"_(("r" - 1))` is
Choose the correct alternative:
The number of ways of choosing 5 cards out of a deck of 52 cards which include at least one king is