The sum of the first 4 terms of a geometric series is 30, and the sum of the infinite series is 32. Find the first 3 terms.

For the geometric sequence a, ar, ar^2,…show that the sequence log a, log (ar), log (ar^2) is an arithmetic sequence

Find a number which, when added to each of 2,6 13 gives three number in geometric sequence

These are the last questions, I apologise for posting up so many, I just really need some help with these, thanks again.