Permutations And Combinations Question 91
Question: $ ^{n}C _{r}+2^{n}{C _{r-1}}{{+}^{n}}{C _{r-2}}= $
Options:
A) $ ^{n+1}C _{r} $
B) $ ^{n+1}{C _{r+1}} $
C) $ ^{n+2}C _{r} $
D)  $ ^{n+2}{C _{r+1}} $
 Correct Answer: CShow Answer
  Answer:
Solution:
 BETA
  BETA 
             
             
           
           
           
          