Let the first term be \(a\) and the common ratio be \(r\).
The third term is \(ar^2\) and the sixth term is \(ar^5\).
Given that \(ar^2 = 8 \times ar^5\), we have:
\(ar^2 = 8ar^5\)
\(r^2 = 8r^5\)
\(r^3 = \frac{1}{8}\)
\(r = \frac{1}{2}\)
The sum of the first six terms is given by:
\(S_6 = \frac{a(1-r^6)}{1-r} = 31.5\)
\(\frac{a(1-(\frac{1}{2})^6)}{\frac{1}{2}} = 31.5\)
\(\frac{a(1-\frac{1}{64})}{\frac{1}{2}} = 31.5\)
\(\frac{a(\frac{63}{64})}{\frac{1}{2}} = 31.5\)
\(\frac{63a}{64} \times 2 = 31.5\)
\(\frac{63a}{32} = 31.5\)
\(63a = 31.5 \times 32\)
\(63a = 1008\)
\(a = 16\)
The sum to infinity is given by:
\(S_\infty = \frac{a}{1-r}\)
\(S_\infty = \frac{16}{1-\frac{1}{2}}\)
\(S_\infty = \frac{16}{\frac{1}{2}}\)
\(S_\infty = 32\)