My advice is not to even try to understand the main approach for NPV – it’s really weird and I’m sure will not happen again. Instead, see the note in the ACCA model answer just beore Q2. That sets out a much more normal approach.
Actual 2012 before tax and interest = $262,322 After tax, before interest = $262,322 x (1 – 0.3) = 183,626
No other adjustments are needed (we have to assume that book depreciation = economic depreciation.)