Home
Class 12
MATHS
.^(n-1)C(r)+^(n-1)C(r-1)=...

`.^(n-1)C_(r)+^(n-1)C_(r-1)=`

A

`.^(n)C_(r+1)`

B

`.^(n)C_(r+1)`

C

`.^(n+1)C_(r)`

D

`.^(n)C_(r)`

Text Solution

Verified by Experts

The correct Answer is:
C
Promotional Banner

Topper's Solved these Questions

  • PERMUTATION AND COMBINATION

    CHHAYA PUBLICATION|Exercise EXERCISE 7B (Very Short Answer Type Questions )|20 Videos

  • PERMUTATION AND COMBINATION

    CHHAYA PUBLICATION|Exercise EXERCISE 7B ( Short Answer Type Questions )|48 Videos

  • PERMUTATION AND COMBINATION

    CHHAYA PUBLICATION|Exercise EXERCISE 7 A ( Long Answer Type Questions )|12 Videos

  • PARABOLA

    CHHAYA PUBLICATION|Exercise Sample Questions for Competitive Exams ( E Assertion -Reason Type )|2 Videos

  • PLANE

    CHHAYA PUBLICATION|Exercise Sample Question for Competitive Examination( E Assertion - Reason Type )|2 Videos

Similar Questions

Explore conceptually related problems

show that ^nC_r+ ^(n-1)C_(r-1)+ ^(n-1)C_(r-2)= ^(n+1)C_r

Show that .^(n)C_(r)+.^(n-1)C_(r-1)+.^(n-1)C_(r-2)=.^(n+1)C_(r) .

Prove that .^(n)P_(r)=.^(n-1)P_(r)+r.^(n-1)P_(r-1) .

Prove that .^nP_r = ^(n-1)P_r + r^(n-1)P_(r-1)

Show that , (.^(n)C_(r)+^(n)C_(r-1))/(.^(n)C_(r-1)+^(n)C_(r-2))=(.^(n+1)p_(r))/(r.^(n+1)p_(r-1))

If n is a positive integer then using the indentiy (1+x)^(n)=(1+x)^(3)(1+x)^(n-3) , prove that ""^(n)C_(r)=""^(n-2)C_(r)+3*""^(n-3)C_(r-1)*""^(n-3)C_(r-2)+""^(n-3)C_(r-3)

.^(n)C_(r)+2.^(n)C_(r-1)+.^(n)C_(r-2)=.^(n+2)C_(r)(2lerlen) .

Prove that , .^(n)C_(r)+3.^(n)C_(r-1)+3.^(n)C_(r-2)+^(n)C_(r-3)=^(n+3)C_(r)

If .^(n+1)C_(r+1):^n C_r:^(n-1)C_(r-1)=11 :6:3, then n r= 20 b. 30 c. 40 d. 50

Find the sum sum_(r=1)^(n) r^(2) (""^(n)C_(r))/(""^(n)C_(r-1)) .