# Test: Geometric Series - Ambitious

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Question 1:   Which of the following are geometric series?
$-\frac{1}{2},\frac{1}{2},-\frac{3}{2}...$
$4,8,16...$
$4,8,12...$
$3,6,10...$
Question 2:   Which of the following are geometric series?
$9,-3,1...$
$2,-4,-9...$
$1.5,1,0.5...$
$\frac{1}{2},\frac{1}{4},-\frac{1}{9}$.
Question 3:   Find a common ratio in the following geometric series: $5,15,45...$
$r=-3$
$r=3$
$r=5$
$r=\frac{1}{3}$
Question 4:   Find the $14$th term in the following geometric series: $12,6,3...$
${a}_{14}\approx 0.0172$
${a}_{14}\approx 0.0031$
${a}_{14}\approx 0.15$
${a}_{14}\approx 0.00146$
Question 5:   Find the sum of the first $5$ terms in the following series: $3\frac{1}{2},7,14,...$
${S}_{5}=98$
${S}_{5}=108.5$
${S}_{5}=98.5$
${S}_{5}=102.5$
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