Ex 8.2, 2 - Chapter 8 Class 11 Sequences and Series

Last updated at April 16, 2024 by

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Ex9.3,2 Find the 12th term of a G.P. whose 8th term is 192 and the common ratio is 2. We know that an = arn 1 where an = nth term of GP n is the number of terms a is the first term r is the common ratio Here, common ratio r = 2 & 8th term is 192 i.e. a8 = 192 Putting an = 192, r = 2 and n = 8 in an 192 = a 2^(8 1) 192 = a 27 192/27 = a a = 192/27 Now we need to find 12th term, we use the formula an = arn 1 Putting n = 12 , a = 192/27 , r = 2 a12 = 192/27 (2)12 1 = 192/27 (2)11 = 192(2)11 7 = 192(2)4 = 192 16 = 3072 Thus, 12th term is 3072

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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 and Computer Science at Teachoo