Check sibling questions
Class 10
Solutions of Sample Papers for Class 10 Boards

Question 8 - CBSE Class 10 Sample Paper for 2018 Boards - Solutions of Sample Papers for Class 10 Boards

Last updated at March 16, 2023 by

The sum of first n terms of an AP is given by S n = 2n 2 + 3n . Find the sixteenth term of the AP.

This is a question of CBSE Sample Paper - Class 10 - 2017/18.

You can download the question paper here  https://www.teachoo.com/cbse/sample-papers/

If Sn = 2n^2 + 3n. Find 16th term of AP - Teachoo - CBSE Sample Paper

Question 8 - CBSE Class 10 Sample Paper for 2018 Boards - Part 2
Question 8 - CBSE Class 10 Sample Paper for 2018 Boards - Part 3

Get live Maths 1-on-1 Classs - Class 6 to 12

Book 30 minute class for ₹ 499 ₹ 299

Transcript

Question 8 The sum of first n terms of an AP is given by Sn = 2n2 + 3n . Find the sixteenth term of the AP. Given Sn = 2n2 + 3n Taking n = 1 S1 = 2 12 + 3 1 = 2 + 3 = 5 So, Sum of first term of AP is 5 But sum of first term will be the first term So, First term = a = 5 Taking n = 2 in Sn S1 = 2 22 + 3 2 S2 = 2 4 + 6 S2 = 8 + 6 S2 = 14 Sum of first 2 terms is 14 Finding 2nd term Sum of first 2 terms is 14 First term + Second term = 14 5 + a2 = 14 a2 = 14 5 a2 = 9 Hence in AP , First term = a = 3 Common difference = d = Second term First term = 9 5 = 4 We need to find 16th term We know that an = a + (n 1) d a16 = a + (16 1) d = a + 15d = 5 + 15 4 = 5 + 60 = 65

Ask a doubt
Davneet Singh's photo - Co-founder, Teachoo

Made by

Davneet Singh

Davneet Singh has done his B.Tech from Indian Institute of Technology, Kanpur. He has been teaching from the past 13 years. He provides courses for Maths, Science, Social Science, Physics, Chemistry, Computer Science at Teachoo.