Approach to calculate after tax nominal required reture

I always got the incorrect ans (or just partly correct ) in calculating the after tax nominal required return in IPS question , part of the reason may be due to the large amount of data , can u guys recommend how to approach this kind of question? The steps to follow or anything need to pay attention , this part usually above 10 marks so I can’t give it up , thanks for help !

Assuming you are talking about individual and assuming retirement beginning now

  1. Calculate spending that needs to be supported by portfolio (Total spending minus any cash inflow (annuity, pension payment, etc))

  2. Calculate investable assets (Total assets minus any short-term cash outlay provided in the problem)

  3. Divide 1 over 2 to get the real return requirement after tax

  4. Add inflation rate to return rate calculated at #3 to get your nominal return requrement after tax.

Thanks for help defacto! I would like to know 1) if there are investment return and investment tax that come anually , is it add/ subtract from investment base or in annual cash flow ? Thanks