Q. Find the sum of the first 50 terms in this geometric series:1+1110+121100…Choose 1 answer:(A) 0.01(B) 0.99(C) 10.91(D) 11
Identifying the series: We are given a geometric series:1+1110+121100+…First, we need to identify the first term (a) and the common ratio (r) of the series.The first term a is clearly 1.To find the common ratio r, we divide the second term by the first term:r=11110=1110
Finding the common ratio: Now that we have the first term a=1 and the common ratio r=1110, we can use the formula for the sum of the first n terms of a geometric series:Sn=(1−r)a(1−rn), where Sn is the sum of the first n terms.We want to find the sum of the first 50 terms, so n=50.
Using the formula for the sum: Let's plug the values into the formula:S50=1−11101(1−(1110)50)
Plugging in the values: Simplify the denominator:1−1110=1111−1110=111So, S50=1111(1−(1110)50)
Simplifying the denominator: Now, we multiply both the numerator and the denominator by 11 to simplify the fraction:S50=11(1−(1110)50)
Multiplying by 11: We can now calculate (1110)50, but since this is a very small number (because 1110 is less than 1 and we are raising it to the 50th power), it will have a negligible effect on the sum. Therefore, we can approximate the sum by ignoring this term:S50≈11(1−0)S50≈11
Approximating the sum: The sum of the first 50 terms in the given geometric series is approximately 11.