2025 CCHY PRELIMS P1 Q26

In sequence A, the first 3 terms are \(a,\ ar,\ ar^2\), where \(a\) and \(r\) are constants. In sequence B, the first term is \(a\) and the same non-zero number is added each time to obtain the next term. The first 3 terms of sequence A are equal to the first, third and sixth term of Sequence B respectively.

1. Show that \(2r^2-5r+3=0\).[3]
2. Find the value of \(r\), justifying your answer.[2]