First slide

Combinations

Question

The value of the expression $x =^{n} C_{0} +^{n + 1} C_{1} +^{n + 2} C_{2} + ... +^{n + r} C_{r}$ is.

Difficult

A

$^{n + r + 1} C_{r}$
B

$^{n} C_{r} + 1$
C

$^{n} C_{n - r}$
D

none of these

Solution

Use $^{n} C_{0} =^{n + 1} C_{0},^{n} C_{r - 1} =^{n + 1} C_{r}$ to obtain $x =^{n + r + 1} C_{r}$

Get Instant Solutions

When in doubt download our app. Now available Google Play Store- Doubts App

Recieve an sms with download link

Doubts App

OR

SCAN ME

Doubts App

Doubts App