You need to refer to the trim sheet on the ATPL Online question bank 'additional information' for it to make sense, but the question is as follows:
Question: Contrary to the forecast given in the LOAD and TRIM sheet, cargo compartment 1 is empty. The take-off centre of gravity in MAC % (Mean Aerodynamic Chord) will be located at:?
I simply adjusted the position of the existing %MAC on the trim sheet by what it would have been if there was no mass in cargo compartment 1. I get 33%MAC. But the answer is stated as 31%MAC.