csat-suneung 2020 Q15

csat-suneung · South-Korea · csat__math-humanities 4 marks Arithmetic Sequences and Series Optimization Involving an Arithmetic Sequence

For an arithmetic sequence with first term 50 and common difference $- 4$, let $S _ { n }$ denote the sum of the first $n$ terms. What is the value of the natural number $m$ that maximizes $\sum _ { k = m } ^ { m + 4 } S _ { k }$? [4 points]
(1) 8
(2) 9
(3) 10
(4) 11
(5) 12

For an arithmetic sequence with first term 50 and common difference $- 4$, let $S _ { n }$ denote the sum of the first $n$ terms. What is the value of the natural number $m$ that maximizes $\sum _ { k = m } ^ { m + 4 } S _ { k }$? [4 points]\\
(1) 8\\
(2) 9\\
(3) 10\\
(4) 11\\
(5) 12

Paper Questions

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