Question 21
**(b)** The fourth and sixth terms of a geometric progression are 36 and 6 respectively. The common ratio of the progression is positive.
Find the sum to infinity of the progression. Give your answer in the form $\dfrac{a}{\sqrt{b} - c}$, where $a$, $b$ and $c$ are integers.
Find the sum to infinity of the progression. Give your answer in the form $\dfrac{a}{\sqrt{b} - c}$, where $a$, $b$ and $c$ are integers.
