CBSE Class 10 Sample Paper for 2019 Boards

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Question 4 - CBSE Class 10 Sample Paper for 2019 Boards - Solutions of Sample Papers for Class 10 Boards

Last updated at April 16, 2024 by

Question 4

If n th term of an A.P. is (2n + 1), what is the sum of its first three terms?

If nth term of an A.P. is (2n + 1), what is sum of its first three

Question 4 - CBSE Class 10 Sample Paper for 2019 Boards - Part 2

Transcript

Question 4 If nth term of an A.P. is (2n + 1), what is the sum of its first three terms? Given an = 2n + 1 We need to find sum of first three terms Finding first three terms a1 = 2(1) + 1 = 2 + 1 = 3 a2 = 2(2) + 1 = 4 + 1 = 5 a3 = 2(3) + 1 = 6 + 1 = 7 1/2 marks for finding a1, a2, a3 So, Sum of first three terms = a1 + a2 + a3 = 3 + 5 + 7 = 15

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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, Social Science, Physics, Chemistry, Computer Science at Teachoo.