What isΣ k=0 to k=28 k^2(28 C k ), where is the number of ways of choosing k items from 28 items?

• ans=406*2^27
  n(n+1)/2=28*29/2=406
  28c0...28c28=2^n-1=2^27
• 11 years agoHelpfull: Yes(7) No(5)
• plz explain it clearly
• 11 years agoHelpfull: Yes(5) No(1)