1. ## Geometric progression

Given the length of the first square is y cm and the ratio of the length of the sixth square to the first square is 1:32

a)find the common ratio of the geometric progression

b)if the sum of the area of the first three squares is 336/256 cm^2.Find the value of y.

2. Originally Posted by mastermin346
Given the length of the first square is y cm and the ratio of the length of the sixth square to the first square is 1:32

a)find the common ratio of the geometric progression

b)if the sum of the area of the first three squares is 336/256 cm^2.Find the value of y.
a) Solve $\displaystyle \frac{y r^5}{y} = \frac{1}{32}$ for $\displaystyle r$.

b) Substitute everything you know (a = y, r = ...., n = 3, S = 336/256) into the formula for the sum of a geometric series and then solve for y.