PCR Dec 2006 Past Paper Help??? URGENT!

DeathCab4Sam

I have left it kind of late to do this paper but im hoping someone can't sleep and will be able to help me. Basically i can't see how they have done Task 1.2 part B.

(b) Calculate how the restriction will affect budgeted stock levels and the production
of stock units needed to meet the new forecasts.

Questions:
http://www.aat.org.uk/servlet/file/Dec%202006%20PCR%20-%20questions.pdf?ITEM_ENT_ID=34576&COLLSPEC_ENT_ID=34&download=1

Answers:
http://www.aat.org.uk/servlet/file/PCR%20-%20model%20answers.pdf?ITEM_ENT_ID=38858&COLLSPEC_ENT_ID=34&download=1

I got all the stuff right up to this but have no idea how they are doing this section.

Please helppppp???