AFMWurrall Plc

Before I answer, in future if you want me to answer, then please ask in the Ask the Tutor Forum for P4. This forum is for students to help each other. :-) In answer to your question, it is an assumption (although to be honest it is difficult for me to think of what else you could have done). However, that is why part (a) asked for you to state your assumptions (and there would be marks for stating them). If you have assumed something different, then no problem - you would still get full marks if you had got the correct figures on your assumptions. There is not often just one correct answer to P4 questions - so much depends on assumptions (just as it does in real life). Provided you state your assumptions (and that they are reasonable/sensible assumptions) then still get the marks even if you assumed different from the answer.