Thanks anonymous and hello Alan,
Yes I can instantly see the logic behind the 2*5 but I will have to think about the -1
Who am I trying to kid - I do not have a clue
We should hire ourselves out to make plausable multilple choice answers for these types of questions.
(Sorry that was a bit offensive - maybe just I should hire myself out. Maybe Chris would like to help me?)
I wonder if anyone would pay us for that?
Why is it 2*5-1? I don't see any intrinsic logic behind the -1