Answer :

Answer:

S6 = 22

Explanation:

Given the series:

[tex]15,5,\frac{5}{3}\cdots[/tex]

The sequence is a geometric sequence with:

• The first term, a = 15

,

• The common ratio, r = 1/3

The sum of nth terms of a geometric sequence is determined using the formula:

[tex]S_n=\frac{a(1-r^n)}{1-r}[/tex]

Substitute a=15, r=1/3 and n=6.

[tex]\begin{gathered} S_6=\frac{15(1-(\frac{1}{3})^6)}{1-\frac{1}{3}} \\ =\frac{15(1-\frac{1}{729})}{\frac{2}{3}} \\ =\frac{15(\frac{728}{729})}{\frac{2}{3}} \\ =\frac{1820}{81} \\ =22.47 \\ \implies S_6\approx22 \end{gathered}[/tex]

The sum of the first 6 ters of the series is 22. (roundd to the nearest integer)

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