(a) An arithmetic progression has a second term of \(8\) and a fourth term of \(18\). Find the least number of terms for which the sum of this progression is greater than \(1560\).

(b) A geometric progression has a sum to infinity of \(72\). The sum of the first \(3\) terms of this progression is \(\dfrac{333}{8}\).

(i) Find the value of the common ratio.

(ii) Hence find the value of the first term.