(1)+(2+3)+(4+5+6)+...+nth brackets find sum

• total no of terms=1+2+3+..n=n(n+1)/2
  and last no. of nth bracket is also n(n+1)/2
  so, this is a a.p series upto n(n+1)/2 havind c.d 1
  s={n(n+1)/2*(n(n+1)/2+1)}/2
• 10 years agoHelpfull: Yes(0) No(0)