2.9: Geometric progression sums

0606/22/O/N/20 — Question 7 · 8 marks

A geometric progression has a first term of 3 and a second term of 2.4. For this progression, find
(a)
the sum of the first 8 terms,
[3]
(b)
the sum to infinity,
[1]
(c)
the least number of terms for which the sum is greater than 95% of the sum to infinity.
[4]