Two sequence patterns for roots of a cubic

Consider the cubic equation \(x^3-12x^2+qx-8=0\), where \(q\) is real. In each of the following cases, its three roots are positive and distinct.

1. The roots form an arithmetic sequence. Find the roots and the value of \(q\).[5]
2. In a different case the roots form an increasing geometric sequence. Find the roots and the value of \(q\).[5]