Example 11 - Chapter 5 Class 10 Arithmetic Progressions
Last updated at Dec. 13, 2024 by Teachoo
Last updated at Dec. 13, 2024 by Teachoo
Example 11 Find the sum of the first 22 terms of the AP : 8, 3, –2, . . . Given 8, 3, –2,………… We have to find sum of first 22 terms . Here, n = 22, a = 8 d = 3 – 8 = –5 Putting there values in formula, Sum = 𝑛/2 [2𝑎+(𝑛−1)𝑑] = 22/2[2 × 8+(22−1)(−5)] = 11[16+(21)(−5)] = 11[16−105] = 11[− 89] = –979
About the Author
Davneet Singh has done his B.Tech from Indian Institute of Technology, Kanpur. He has been teaching from the past 14 years. He provides courses for Maths, Science and Computer Science at Teachoo