Bored of Studies Trial Discussion Thread. (1 Viewer)

[Carrotsticks]

I was thinking about that before actually. Maybe just tell the odd integers to piss off?

One does not simply tell the odd integers to piss off.

 

[Sy123]

One does not simply tell the odd integers to piss off.

Yeah when I was doing that question I got up to the n/2 step but I didnt want to continue because I thought it was mathematically incorrect to assume n was even lol. So I ended up not doing it :/

 

[asianese]

One does not simply tell the odd integers to piss off.

rofl

 

[gr_111]

I was thinking about that before actually. Maybe just tell the odd integers to piss off?

lol'd at this. One thing carrot, just make sure BoardOS doesn't get hold of your paper.

 

[asianese]

why?

 

[deswa1]

My multiple choice answers:

1. B
2. C
3. D
4. A
5. C
6. B
7. D
8. D
9. B
10. D

anyone the same or different?

Yeah got the same except for Q1 which I got D (which has already been pointed out)

Did anyone get the last perms question? part biii of Q11

I have a feeling carrot may have underestimated its difficulty. If there was no double H's it would have been fine... but maybe there is an easy way

Yeah you can do it without cases and its pretty easy though I think I got it wrong because I forgot about the H's - though the method is easy to adjust even if you remember the H's so its easy if you know how to do it- I'm just a retard and made a silly... Will show you guys how to do it later if you want

I was thinking about that before actually. Maybe just tell the odd integers to piss off?

Haha lol. You should so do this in HSC

 

[AAEldar]

Just had a quick scan through of the paper, don't think I'll get some time to attempt it myself but would just like to say well done to Carrot, Trebla, seanieg and whoever else had input on it - a very solid paper.

Good to hear you guys enjoyed the challenge as well!

 

[Carrotsticks]

edit no, wtf.

Here's something to start you off:

 

[Trebla]

Here's something to start you off:

Another hint, consider



and

 

[barbernator]

Here's something to start you off:

Another hint, consider



and

he came, he considered, he did not conquer. nvm ill have a good think later

 

[Sy123]

I think Ive got it:



I cant be bothered latexing it all up

 

[barbernator]

I think Ive got it:

View attachment 26460

I cant be bothered latexing it all up

oh yes ofc! well done

 

[Sy123]

I still cant to that perms one lol, can someone post their solution up

 

[barbernator]

I still cant to that perms one lol, can someone post their solution up

Oh lol got it.

Taking the 7 consonants, there are 7!/2 ways to arrange. Now there are 8 spots for vowels and they can be put in in 8P4/3! ways. I think that's right...

 

[Sy123]

Oh lol got it.

Taking the 7 consonants, there are 7!/2 ways to arrange. Now there are 8 spots for vowels and they can be put in in 8P4/3! ways. I think that's right...

Could you explain how you got 8 spots left for vowels?

 

[deswa1]

Could you explain how you got 8 spots left for vowels?

Ok this is called the insertion method- I won't give the answer but I'll tell you how to do it and you should be able to do the rest. So we don't want any two vowels next to each other. If we set up the other letters as like 'barriers' then by placing one vowel between the barriers (i.e. not two between the same barrier), then by definition all vowels are seperated as required. Now we have 7 other letters so there are seven barriers and hence 8 spaces for the vowels to go (draw this out if you can't picture it). Now we just need to place the 4 vowels in these 8 different spots so just use your normal combinatorics (accounting for the triple O etc.) and then you rearrange the arrangements of the 'barriers' and you're done.

Does that make sense?

 

[Carrotsticks]

Ok this is called the insertion method- I won't give the answer but I'll tell you how to do it and you should be able to do the rest. So we don't want any two vowels next to each other. If we set up the other letters as like 'barriers' then by placing one vowel between the barriers (i.e. not two between the same barrier), then by definition all vowels are seperated as required. Now we have 7 other letters so there are seven barriers and hence 8 spaces for the vowels to go (draw this out if you can't picture it). Now we just need to place the 4 vowels in these 8 different spots so just use your normal combinatorics (accounting for the triple O etc.) and then you rearrange the arrangements of the 'barriers' and you're done.

Does that make sense?

My my... this method looks familiar =p

And the answer is:

 

[deswa1]

My my... this method looks familiar =p

Haha yes I have to give acknowledgements- Carrot taught me this. I think I still got the question wrong though because I think I forgot about the H's

Oh and after you taught me this, I went to school and showing people and a lot of them were like wow so thanks to you I got bonus rep points lol. But then I went to show one of my best friends (who topped X1 and stuff) and then he was like "oh this is the insertion method" and was full like that it was a standard technique haha

 

[twinklegal19]

As a year 11 who had no knowledge of projectile motion, binomial theorem, perms & combs etc, I died several times over in the test haha.

It was an interesting experience to say the least

I'm so happy that I could angle chase the circle geo question though

TAKE THAT CARROT!

hehe

 

[Sy123]

Ok this is called the insertion method- I won't give the answer but I'll tell you how to do it and you should be able to do the rest. So we don't want any two vowels next to each other. If we set up the other letters as like 'barriers' then by placing one vowel between the barriers (i.e. not two between the same barrier), then by definition all vowels are seperated as required. Now we have 7 other letters so there are seven barriers and hence 8 spaces for the vowels to go (draw this out if you can't picture it). Now we just need to place the 4 vowels in these 8 different spots so just use your normal combinatorics (accounting for the triple O etc.) and then you rearrange the arrangements of the 'barriers' and you're done.

Does that make sense?

Ah that is genius heh. Well this method will probably help me with alot of perms questions. Thanks (and props to carrot of course)