| Exam Board | OCR |
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| Module | H240/01 (Pure Mathematics) |
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| Year | 2019 |
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| Session | June |
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| Topic | Geometric Sequences and Series |
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7 In this question you must show detailed reasoning.
A sequence \(u _ { 1 } , u _ { 2 } , u _ { 3 } \ldots\) is defined by \(u _ { n } = 25 \times 0.6 ^ { n }\).
Use an algebraic method to find the smallest value of \(N\) such that \(\sum _ { n = 1 } ^ { \infty } u _ { n } - \sum _ { n = 1 } ^ { N } u _ { n } < 10 ^ { - 4 }\).