Clearly, 5 x 2 = 10, 10 x 2 = 20, 20 x 2 = 40,..... So, the series is a G.P. in which a = 5 and r = 2. Let 1280 be the rath term of the series. Then, 5x2ⁿ⁻¹ = 1280 ⇔ 2ⁿ⁻¹ = 256 = 2⁸ ⇔ n - 1 = 8 ⇔ n = 9.
Which term of the series 5, 10, 20, 40, ..... is 1280?
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This question is part of 💬 Verbal Reasoning within the broader 🧠 Aptitude Mastery subject and appears in the DemoPaper-Pakistan preparation collection. Reviewing the answer together with nearby questions helps reinforce the underlying concept and identify how it may appear in competitive exams.