Love hate relationship with Permutations (1 Viewer)

[~Fire Jade~]

Permutations....
Very confusing (which moron created it?):burn:
Anywayz, I need help with it. I understand the diff between permutations and combinations but I continually intepret the questions wrong which in turn means I get a wrong answer- very bad.

I don't know what to do so I'm wondering whether people around here can explain to me whether there are 'typical' or certain questions which mean a certain method has to be used. Please help. In dire need of help from those who get permutations or those who don't but are willing to offer ideas!
\(^-^)/

*Thanx*

 

[pLuvia]

Permutations is the number of arrangments of different/identical objects where the order of the objects matters

Combinations is the number of different ways of choosing objects where order doesn't matter

To answer your question no, most questions require you to use both techniques. In actual fact, permuations can be derived from combinations. Since with permutations you are actually choosing the objects then arranging it, where as with combinations you are just choosing.

If there question states "how many ways are there of choosing blah blah" it's a combination question, when the question asks "how many ways of arranging blah blah", its a permutation question

 

[~Fire Jade~]

Kinda knew that but I don't understand the questions...I work out an answer but it's wrong and I suffer continuous disappointment. lols =)

 

[YannY]

permutation: We have A,B,C,D and we want to arrange it.

we can put 4 in the first space. 3 in the second space. 2 in the 3rd space and 1 in the final space.

Why is is a multiplication relationship you might ask?

Well think about it, for whatever we put in the first slot - theres 3 that can go in the second space. But since theres 4 that can be put into the first space, there will be 4x3 ways for the first two spaces. This is continued till everything is satisfied.

 

[~Fire Jade~]

Thanks for the permutations help, but 3unitz, why would you draw circles to do a question? I'm sorta confused....=.=

 

[conics2008]

fck perms and com's, this topic is full of shit.. i hate it soo much....

 

[~Fire Jade~]

this topic is full of shit.. i hate it soo much....

Yup, me too...><
Do permutations and combinations take up a lot of marks in the HSC (I'msincerely hoping it isn't)?

 

[.deimonic]

I think perms and combs are fun . lol well I'm not terrific at it or anything but you don't need tedious piles of working. What I find with these questions is you really gotta read the question and interpet it otherwise you'll screw it.
Drawing diagrams also helps and remember to consider all possible arrangements/combinations, if you're careless and leave anything out you'll get the answer wrong.

 

[kooltrainer]

lol yeh.. sumtimes its fun and u can finish whole exercise in one page.. its complicated at first but u'll get the hang of it after doing sum examples

 

[selablad]

I remember when we were doing this topic, my maths teacher told us that statistics is the slut of the mathematical world

 

[z600]

Yes P & C are a bitch to do as I found out revising for my half yearlies. But the thing with P & C is you need to find tricks and just keep doing pratices and eventually you'll remember each case. Some tips

*When arranging in a circle, pretend the people are sitting in a straight line but the first person is x1

*When there are restrictions, deal with them first. And count the restrictions as a group

*When it says "atleast" try 1-p(complementary events)

*Remeber, people are different, but objects are not (unless specified)

*There are just little things you need to remeber to do like multiply by a certain way it can be done etc, so do more and more questions!

 

[~Fire Jade~]

Thnx....this advice is helpful to me...(but I still hate it heaps)
Waaaahhhh....which moron came up and invented this topic to complicate the lives of Yr 12 Maths Ext 1 Students....
I suck at this....tried a few questions...and failed spectacularly....

 

[DownInFlames]

Yup, me too...><
Do permutations and combinations take up a lot of marks in the HSC (I'msincerely hoping it isn't)?

Got to know the theory. It comes in useful and there could be a whole question on it if you're unlucky.

You will suffer continuous disappointment with this topic as it is quite hard to grasp...

Maybe post questions up that you don't understand and we can explain why you have to do it a certain way. A lot of practice is the only way forward, unfortunately, but if you study it a decent amount now you'll be alright for the exams.

 

[~Fire Jade~]

You will suffer continuous disappointment with this topic as it is quite hard to grasp...Maybe post questions up that you don't understand and we can explain why you have to do it a certain way. A lot of practice is the only way forward, unfortunately, but if you study it a decent amount now you'll be alright for the exams.

Nooooo!!!!! (btw that was a howl of despair at the thought of perms and combinations as a whole HSC question. Ummm, thnx for ur support...I have a stupid upcoming assessment tasks on permutations ><
So I'll post up questions on perms in upcoming days and everybody can try answer the questions! Thnx so much! =)
....I still really hate perms....

 

[Cob-was-here]

Um......whats a permutation? is it a bad sign that i have never heard this term?