Math Help

<p>Can someone explain how to do this problem step-by-step? Thanks!</p>

<p>ImageShack</a> - Hosting :: 19192130ge9.png</p>

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<li><p>Okay, so this is an infinite geometric series, meaning that there is a constant ratio between consecutive terms, which in this case is 0.15. A Geometric series can best be described as an infinite series of numbers with a finite sum. For instance, with a common ratio of 1/2, 1/2 + 1/4 + 1/8 + 1/16 + 1/32.....have a finite sum of 1.</p></li>
<li><p>In this case, we need to find a, which is the first number in the series. So we take the formula given, a/1-r = finite sum of a geometric series. Here it says that the sum is 200, so set the equation equal to 200 and substitute .15 in for r which is also given in the question. 200 = a/1-0.15 multiply both sides by 0.85 and you get 170 = a.</p></li>
<li><p>The question clearly states that a is equal to the first term in the series, however, we are looking for the second one. We know that the common ratio is 0.15, so multiply 170 by 0.15 and you get 25.5 which turns out to be the second term and the answer which is F.</p></li>
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<p>ok thanks a lot!</p>