Pauline and her insurance scheme...

Hi, was just wondering if anyone could help me with a few questions, had a look all through my notes and there doesn't seem to be anything that I can use in these situations (there probably is, but you know when you get stuck you just cant seem to think it through straight!)

okay, so

C2:

6 The ammount of money which Pauline pays into and insurance scheme is recorded each day. The ammount which pauline pays in during the nth year is £Aη. The first three values of Aη are given by:

A1=800 A2=650 A3=530

The recorded amounts may be modelled by a law of the form

Aη+1=pAη+q

Where p and q are constants

a) Find the value of p and the value of q

b) Find the limiting value £V using and equation for V