About Nose weight of the centre-axle trailer: which statement is WRONG?
The text literally refers to 'the load under the coupling of a centre-axle trailer'.
The 50 kg maximum applies specifically to a centre-axle trailer WITH A MASS OF AT MOST 750 KG.
For a centre-axle trailer above 750 kg, the nose weight may be at most 1% of the permitted maximum mass.
There is no '75 kg' in the book. Up to 750 kg TMM a maximum of 50 kg applies; above 750 kg TMM a minimum of 1% of the permitted maximum mass applies. '75 kg' is a quick-prep rule of thumb, not a book limit.
Explanation
trap: inverted limit. Book p.230 - 'may not be less than 1%' is a minimum, not a maximum. At 1,200 kg TMM the nose weight must therefore be at least 12 kg; more is always allowed