Homework Study Helpers! =P discussion

Please help! I love maths and am pretty good at it but I just can't fathom stats!

Here is one of many q's I can't do...

In Mr Kendall's cupboard there are 3 tins of baked beans and 2 tins of pineapple. Unfortunatly his daughter has removed all the labels for a school project and so the tins are identical in appearence. Mr Kendall wishes to use both tins of pineapple for a fruit salad. He opens tins at random until he has opened two tins of pineapples.

Let X be the number of tins that Mr Kendall opens.

Show that P(X=3)=1/5

errr... lemme try it

Mr. Kendall wants two tins of pineapple, so he can not get them in one, so P(X=1) = 0. (For that matter P(X=0) = 0, too.)
In order to get it in two, the first tin would have to be pineapple (2 out of 5 = 2/5), and the second tin would be pineapple as well, (1 out of 4 = 1/4), and the probability is 2/5 × 1/4 = 1/10.

In three means that either the first was pineapple and the second beans, or vice-versa, followed by a pineapple: [(2/5 × 3/4) + (3/5 ×2/4)] × 1/3 = (3/10 + 3/10) × 1/3 = 3/5 × 1/3 = 1/5

Well explained, Δx Δp ≥ ½ ħ.

I'm assuming that this is on the core AS stats module, Nicolle. We could avoid the stats and just study mechanics in my A-level days. Until uni.....

@ Δx Δp ≥ ½ ħ
Thanks so much!

@ Steve
We didn't get a choice, though we are doing Mechanics at A2 and when I take up further maths AS in september I do another mechanics course.

The first module I did in physics was mechanics and I got a D(better than I expected as my teacher doesn't explain things in a way I understand and I really didn't get most of the paper) so I will have to improve dramatically in the maths module.

I have C1 C1 and S1 exams in about 3 weeks! I'm very confidant with the first two not the S1 it has too many words!

Best of luck with those Nicolle, I'm sure you'll do fine. Exam dates for us in the UK seem to be getting slightly earlier every year for some reason.

I know it is so frustrating, we have only got 6 hours of lessons till the first exams and we haven't actually learnt all the syllabus yet...looks like no revision in class time.

Umm...guys there was already a topic for statistics lol

Yeah it is kind of part of statistics actually, but it's not all statistics, but they are part of it.

I'm writing a paper for my Applied Statistics class about the Clean Plate Club, the idea of eating everything on your plate regardless of whether you're hungry or not. How can I collect data without having to survey people? If you do have an idea that involves surveying people, I welcome it too. Do you have surveying websites you can recommend?

Google Form?

survey monkey?