Rockhampton's Rock Mystery Cache

Like its namesake ‘The Rock’, it is intended that “Rockhampton’s Rock” will be a bank, or more specifically a geocoin geocache. I would prefer it if withdrawals weren’t made without deposits (please leave something in there to maintain some liquidity), but just like banks, additional TB deposits of any nature are always welcome. But even if you don’t have a deposit, please feel free to ‘discover’ the coins in the cache, as there is nothing stopping cache visitors noting the tracking numbers of any coins in residence. The initial deposit was predominately made up of coins from my own collection, with a top up made by a couple of other cachers who have graciously agreed to their coins also being deposited.

But finding the cache will not be as easy as walking into any local branch. It will require some investigation and basic geography, a bit of trigonometry and some elementary calculations … Oh, and of course, a cacher’s eye, to grab the prize.

At the time of placing (July 2007) ‘The Rock’ had several branches in the imediate locale area, and distances from those branches to the cache GZ are provided.

1. (Head Office Branch) Cnr Archer & Bolsover Streets, Rockhampton 7.940km
2. Stockland Shopping Plaza Rockhampton 5.626km
3. Rockhampton CBD 7.780km
4. Allenstown Plaza,Rockhampton 9.416km
5. Frenchville Shopping Centre 3.929km

Distances are approximately from the front doors of the branch or adjacent ATMs. There is no need to look suspicious in front of the buildings or get photographed with a GPS in front of an ATM, a quick fix from a vehicle close to the spot will do fine (or maybe even a bit of Google Earth will suffice), as the ability to reduce error circles and fine tune a position has been accounted for in the next section.
(For the Allenstown Branch – use the Centre’s North West door)

Given that there could be quite a few discrepancies as to the final coordinates, due to variable fixes with respect to branch locations (not to mention a poor intersection of distance arcs due to the geographic position of the branches in relation to the GZ) … solve for the following unknowns, to tie down the last few meters … after determining a position.

S yy.yy.yAB & E xxx.xx.xCD

For A
you need the telephone number of the head office 07 49ab cdef
where A = (a + 2*b + c) / 2*(d + e + f)

For B
you need the telephone number of the agency’s hotline: 1800 abc def
where B = (e + f + b – a) * (c + d – f)

For C
you need the net profit after tax, in the 2006 Shareholder report: a.bcd million
where C = (a * c) + b/d + c

For D
D = d – c*(a / (b + c))
where a = the number of letters in the name of the town with the most western branch
and in what year did/will ‘The Rock’ celebrate its 40th anniversary xxbc
d = the number of letters in the name of the town with the current most southern branch

A ‘First to Find’ geocoin is up for grabs as a FTF prize, which hopefully will also be deposited into the cache, once activated, or at least logged in and out befor proceeding on its own travels.