What it basically means is that for each day the partner works, 20 euro is deducted but the maximum deducted in one week is 60.
So if they work 1 days, 20 is deducted
2 days, 40
3 days, 60
4 days, 60
5 days, 60
6 days, 60
so (I think) calculation would be
Personal rate (claimant) 204.30 (maximum rate)
Qualified adult 135.60 (maximum rate)
(420 per week - 60 max) * 60% ...



