I need help on q3 a and b when you click this link

Key Maths: Summary and Practice ... - Google Book Search

Please could you help me by showing the working out

I also need help on this probability question. I've worked out the first part which is 7/15 i think but I do not know how to do the 2nd part.

Its q2 at the bottom of the page

Key Maths: Summary and Practice ... - Google Book Search

Thank you