An arithmetic series has first term $1000$ and common difference $-1.4$ negative terms of the series

Question

An arithmetic series has first term $1000$ and common difference $-1.4$ negative terms of the series. Find the sum of the first $20$ negative terms of the series. Find the sum to first $n$ terms of the geometric series $2+\frac{1}{2}+\frac{1}{8}+...$. Hence or otherwise, find the least value of $n$ for which the sum of the next $n$ terms is less than $\mathrm{0}\mathrm{.008}$.

Accepted Answer

(a) -286 (b) least n = 5

CJC APGP Tutorial Q4

CJC APGP Tutorial Q4

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