5. The first three terms of a geometric series are \(4 p , ( 3 p + 15 )\) and ( \(5 p + 20\) ) respectively, where \(p\) is a positive constant.
- Show that \(11 p ^ { 2 } - 10 p - 225 = 0\)
- Hence show that \(p = 5\)
- Find the common ratio of this series.
- Find the sum of the first ten terms of the series, giving your answer to the nearest integer.