calculation of Average capital employed

Radhika (na) (25 Points)

17 March 2019  
Generally ,to calculate the average capital employed we deduct 1/2 of PAT from closing capital employed to arrive at Avg Capital Employed but in various questions I found out that only closing capital employed had been taken to arrive at normal profit in the calculation of goodwill inspite of the fact that PAT has been given in the question and still no adjustment has been done in regard to that.
can someone please clarify in which situation we do such adjustment??
Please clear this doubt