Last updated at Dec. 8, 2016 by Teachoo

Transcript

Ex 5.2 ,11 Which term of the A.P. 3, 15, 27, 39, will be 132 more than its 54th term? 3, 15, 27, 39, First we need to calculate 54th term We know that an = a + (n 1)d Here, a = 3 d = 15 3 = 12 n = 54 Putting values in formula a54 = a + (n 1) d = 3 + (54 1) 12 = 3 + 53 12 = 3 + 636 = 639 So, 54th term = a54 = 639 We need to calculate term which is 132 more than 54th term i.e. should be 639 + 132 Therefore an = 771 We need to find n Putting values in formula an = a + (n 1) d 771 = 3 + (n 1) 12 771 3 = (n 1) 12 768 = (n 1) 12 768/12 = n 1 64 = n 1 n 1 = 64 n = 64 + 1 n = 65 So, 65th term is 132 more than 54th term

Chapter 5 Class 10 Arithmetic Progressions

Serial order wise

About the Author

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.