# SPM Practice 2 (Geometric Progression) : Question 10

Question 10

In a geometric progression, the first term is 27 and the fourth term is 1. Calculate
(a) the positive value of common ratio, r,
(b) the sum of the first n terms where n is sufficiently large till ${r}^{n}\approx 0$  .

[Hint : Remember-
the sum of the first n terms where n is sufficiently large till ${r}^{n}\approx 0$  = ${S}_{\mathrm{\infty \right]}}$