I need to find either model solution/mark scheme for 2 A level
mathematics past papers.  (pure...probably P1 and P2) im not sure
which year they are from.  They each have 8 questions.  paper 1
question 1 which says prove that E((rpower2) -r -1)=(1/3)(n-2)n(n+2)
paper 2 has question 4 which says "the specification for a new
rectangular car park states that its length,x m, is to be 5m more than
its width..."
I would like to know which exam board and year the papers are from and
where i can find solutions.

I honestly doubt very much that anyone will be able to find this
answer for you from the information you have.  If the papers were
given to you by your teacher, s/he will probably know the source and
know if any model answers or marking schemes are available.