6. Foreign investment appraisal - Example 4

I have absolutely no idea as to which book you found the example in !! If you will be more specific then I will try and answer.

My apologies, I was referring to Example 4 on page 40 of the opentuition AFM notes and the answer given on ACCA (AFM) lectures - Discounted cash flow techniques (part 3). The question stated "An amount equal to the amount of the tax allowable depreciation is required each year for the maintenance of non-current assets." Why it's the maintenance taken as a deductible expenses to calculate tax?

You have a valid point in that the expenses would probably be allowable for tax. However as I do explain the free lecture working through this example, this is something that the current examiner regularly puts in questions and he always ignores any tax implication.