I've observed that there is some tolerance on this site for helping with homework questions, where by "some" I mean "very little". This link seems useful for helping you actually learn the topic:
Mark it's not really about thanks, well not for me anyway, but as this was your third of these maths quiz questions there was no evidence that you'd even looked at the previous two.
apologies prudie. i did mark some answers as the best, i am new to this site and just getting to know the etiquette, thank you for steering me in the right direction