The sale, \(S\), in dollars made by a student-run café \(h\) hours after opening is modelled by \(S=320+80h-8h^2\), where \(0\le h\le12\).
By expressing \(S\) in the form \(A-B(h+C)^2\), where \(A\), \(B\) and \(C\) are constants, find the time at which the sale is greatest and state this greatest sale.[4]
After a promotional campaign, the sale at each time was found to be 25% higher than before. State the time at which the sale is greatest and the value of this biggest sale.[2]