Guest

8. Find the sum of first 51 terms of an AP whose second and third terms are 14 and 18 respectively.

8. Find the sum of first 51 terms of an AP whose second and third terms are 14 and 18 respectively.

Grade:12th pass

1 Answers

Pawan Prajapati
askIITians Faculty 60796 Points
one year ago
Given that, Second term, a2 = 14 Third term, a3 = 18 Common difference, d = a3−a2 = 18−14 = 4 a2 = a+d 14 = a+4 a = 10 = First term Sum of n terms; Sn = n/2 [2a + (n – 1)d] S51 = 51/2 [2×10 (51-1) 4] = 51/2 [2+(20)×4] = 51 × 220/2 = 51 × 110 = 5610

Think You Can Provide A Better Answer ?

Provide a better Answer & Earn Cool Goodies See our forum point policy

ASK QUESTION

Get your questions answered by the expert for free