Simple sums

I had an email yesterday from someone seeking to contest my assertion that, given the information that the council had provided to Cllr Rob Summons, it was easy to work out the “commercially confidential” builder’s rates that the council has been keeping from me for the last few months.
It would be most surprising if this was one of my highly-intelligent regular readers, so I can only assume someone had blundered in here after clicking on a link on that other website.
According to Cllr Summons, he had been told that the grant was £1,052.47 and the area of hack off, render and paint was 40 sq metres.
The grant rate for structural and fabric repair is 70%.
I wrote: “Anyway, we now have the amount of grant, the quantity of work done and the percentage rate of grant, which can be found in the publicly available procedure manual.
As the mathematicians among you will have already worked out, with that range of information even Jacob Williams could reconstruct the complete BoQ including the builder’s precious “commercially confidential” rates which the council has been trying its best to conceal from me for the past nine months.”
So, how is this done?
Well, £1,052.47 is 70% of £1,503.53 (rounded up to the nearest penny) divided by 40, equals £37.58 per sq metre.
What isn’t quite so easy to work out is why this is less than half the £78 per sq metre the same builder charged for exactly the same three-stage operation just round the corner at 16-19 Commercial Row.