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Ex 8.3, 1
Last updated at June 9, 2026 by Teachoo
Class 9
Chapter 8 - Predicting What Comes Next: Exploring Sequences & Progress
- Definition
- Explicit Rule for a Sequence
- Recursive Rule for a Sequence
- VirahΔnkaβFibonacci sequence
- Exercise Set 8.1
- Arithmetic Progressions
- Visualising an AP
- Sum of the First n Natural Numbers
- Exercise Set 8.2
- Geometric Progressions
- Fractals as a GP Sequence
- Visualising a GP
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Exercise Set 8.3
- End-of-Chapter Exercises
Transcript
Ex 8.3, 1 Find the 12th term of a GP with common ratio 2 , whose 8th term is 192. We know that for a GP nth term = π_π=γππγ^(πβπ) Given that Common ratio = r = 2 Also, given that 8th term is 192 8th term = 192 a8 = 192 Putting n = 8, r = 2 in an formula π Γ π^(π β π)=πππ π Γ 2^7=192 π=πππ/π^π Now, we need to find 12th term, Using our formula π_π=γππγ^(πβπ) Putting n = 12 , a = 192/27 , r = 2 π_ππ=πππ/ππ Γ π^(ππ β π) π_12=192/27 Γ 2^11 π_12=192 Γ2^11/2^7 π_12=192 Γ 2^(11 β 7) π_ππ=πππ Γ π^π π_12=192 Γ 16 π_ππ=π,πππ Thus, 12th term is 3072
