Ok, so I've got quite a few questions to get through over the next few days.

I finished question (a) in 5 minutes, no problem.

Question (b), I've just been searching for combinations of the numbers 1-10 that when added together will gove 150cm (10cm x 15cm frame), but so far, none of the combinations I've found have fit in the frame.

Is there any way to actually find these values without just guessing and checking?

As for questions (c) and (d), I have absolutely no idea where to start... Could anyone help?