3. The third and fourth terms of a geometric series are 6.4 and 5.12 respectively.
Find
- the common ratio of the series,
- the first term of the series,
- the sum to infinity of the series.
- Calculate the difference between the sum to infinity of the series and the sum of the first 25 terms of the series.
[0pt]
[P1 January 2001 Question 5]