1. Class 10
  2. Solutions of Sample Papers for Class 10 Boards
  3. CBSE Class 10 Sample Paper for 2019 Boards

Question 4 - CBSE Class 10 Sample Paper for 2019 Boards

Last updated at Oct. 1, 2019 by

Question 4

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

Slide11.JPG

Slide12.JPG

Subscribe to our Youtube Channel - https://you.tube/teachoo

  1. Class 10
  2. Solutions of Sample Papers for Class 10 Boards

    3. CBSE Class 10 Sample Paper for 2019 Boards

    CBSE Class 10 Sample Paper for 2018 Boards →

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

Class 10
Solutions of Sample Papers for Class 10 Boards

About the Author

Davneet Singh's photo - Teacher, Computer Engineer, Marketer
Davneet Singh
Davneet Singh is a graduate from Indian Institute of Technology, Kanpur. He has been teaching from the past 9 years. He provides courses for Maths and Science at Teachoo.