Identify Geometric Series: The given series is a geometric series with the first term a=1000 (when k=0) and the common ratio r=x (since each term is x times the previous term). The sum of a finite geometric series can be found using the formula Sn=(1−r)a(1−rn), where n is the number of terms.
Calculate Number of Terms: In this case, the number of terms n is 10 (from k=0 to k=9). We can plug the values into the formula to find the sum: S10=(1−x)1000(1−x10).
Use Sum Formula: We are given that the sum of the series is equal to 5×60×1000. This means that S10=5×60×1000.
Set Up Equation: Now we can set up the equation 1000(1−x10)/(1−x)=5×60×1000 and solve for x.
Simplify Right Side: First, we simplify the right side of the equation: 5×60×1000=300,000.
Divide by 1000: Now the equation is 1000(1−x10)/(1−x)=300,000. To simplify further, we can divide both sides by 1000, which gives us (1−x10)/(1−x)=300.
Consider x=1: This equation is not straightforward to solve algebraically for x, as it involves a polynomial of degree 10. However, we can notice that if x=1, the denominator becomes zero, which is not allowed. Therefore, x cannot be 1. If x were to be 1, the left side of the equation would be undefined, which cannot equal 300. This suggests that there might be an error in the problem statement or a misunderstanding of the problem as it stands.
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