What is the sum of first 30 terms of an A. P., whose n th term is 2 + 1/2n ?

• 2+1/2n=(4n+1)/2n
  Here first term a = T1 = (4n +1)/2n = 5/2
  and last term = T30 = ((4*130)+1)/(2*30) = 121/60
  S19 = n(a +l)/2 = 30(5/2 +121/60)/2 = 67.75(ans
• 12 years agoHelpfull: Yes(4) No(4)
• Pls check if terms are in AP with given condition.
  T1=5/2
  T2= 9/4
  T3= 13/6
  Difference between T1 and T2 = 5/2-9/4 = 1/4
  Diff between T3 and T2= 9/4-13/6 = 1/12
  
  pls check if condition for nth term is correct.
• 12 years agoHelpfull: Yes(1) No(0)