The sum of the first and the 9th term of an arithmetic progression is 24. What is the sum of the first nine terms of the progression?

• Sum of the first nine terms of the progression is 108.
  
  ** Sum of first 'n' terms of an A.P is = n/2(first term + last term)
  where
  n = number of terms
  
  ** Sum of the first 9 terms is = 9/2(first term + last term)
  
  ** Sum of the first 9 terms is = 9/2(24) ==> 108
  where
  first term + last term = 24
• 12 years agoHelpfull: Yes(3) No(1)
• sum of the first nine terms of the progression 24*9/2 = 108
• 12 years agoHelpfull: Yes(1) No(1)
• The sum S of the first n values of a finite sequence is given by the formula:
  
  S = 1/2(a1 + an)n, where a1 is the first term and an the last.
  given a1+an=24;
  so,1/2(24)*9=108;
• 11 years agoHelpfull: Yes(0) No(0)