ACCA P2 Group SFP – Change in structure – Example 5

I have two questions.

1. Well calculating Goodwill, don’t you have to separate GW attributed to Parent and NCI?

For jones in this question pre acq value was 110 so wouldn;t parent GW be

120-(110×90%)= 21?

Sub
13-(110×10%)=2

Thus total GW of 23 as shown in the question?

2.

Also when valuing the 20% sold, I’m confused on whether it should be

[120+the attributable GW+ post acg retained earning (90% x10)}x20%
Then use this as the increase in value of NCI

Please advise