Q. Find the sum of the first 9 terms of the following series, to the nearest integer.22,44,88,…Answer:
Identify type of series: Identify the type of series.The given series is 22,44,88,…, which appears to be a geometric series because each term is obtained by multiplying the previous term by a constant.
Determine common ratio: Determine the common ratio r of the series.To find the common ratio, divide the second term by the first term.2244=2Common Ratio r: 2
Use formula for sum: Use the formula for the sum of the first n terms of a geometric series.The formula for the sum of the first n terms (Sn) of a geometric series is:Sn=a⋅(1−rn)/(1−r), where a is the first term and r is the common ratio.
Calculate sum of terms: Calculate the sum of the first 9 terms.First term (a)=22Common ratio (r)=2Number of terms (n)=9S9=22×(1−29)/(1−2)
Perform calculations: Perform the calculations.S9=22×(1−512)/(1−2)S9=22×(−511)/(−1)S9=22×511S9=11242