Question

For this infinite geometric series, find r.36 + 18 + 9 ...

Answer 1

\[r=\frac{ nth~ term }{ \left( n-1 \right)th~term }=\frac{ a _{2} }{ a _{1} }=\frac{ a _{3} }{ a _{2} }=....=?\]

Answer 2

It would seem to describe\[36\sum_{k=0}^{\infty}\frac{1}{2^k}\]From that, we might be able to get a value for r.