Thread: Westpac Maths Comp!

1. Westpac Maths Comp!

hey guys, lookoutastroboy here,

all of you peeps who have done the westpac maths comp and have got distinctions and above, how the hell do you achieve such a mark.
I'm accelerating yr 10 maths by the half year in yr 9, and the intermediate level is quite hard.

The question is:

How do you learn how to do the questions in there even when you have learnt the whole content of your maths for your appropriate year?

Example: A student is in Yr 9. He does the Yr 9 Intermediate MWestpac Maths Comp Paper.

I find that even when you know all the stuff for your year of maths, the questions are harder than that and require even higher level of maths...

By lookoutastroboy.

2. Re: Westpac Maths Comp!

Originally Posted by lookoutastroboy
hey guys, lookoutastroboy here,

all of you peeps who have done the westpac maths comp and have got distinctions and above, how the hell do you achieve such a mark.
I'm accelerating yr 10 maths by the half year in yr 9, and the intermediate level is quite hard.

The question is:

How do you learn how to do the questions in there even when you have learnt the whole content of your maths for your appropriate year?

Example: A student is in Yr 9. He does the Yr 9 Intermediate MWestpac Maths Comp Paper.

I find that even when you know all the stuff for your year of maths, the questions are harder than that and require even higher level of maths...

By lookoutastroboy.

5. Re: Westpac Maths Comp!

Originally Posted by bored of sc
High Distinction is the top 2% although this percentage can vary.

Distinction is the next top 13% (I think).

Credit is the next 35%.

Participation is the bottom 50%.

I think... if you look at it this way and credit is pretty darn good (top half of the state).

I got a HD is year 8 and a D is year 10 but other than that it has been constant credits for me.

Yeah, don't worry about it - the last questions are insane - and you don't have a calculator.
I think that's right. Prize money is like 0.3% and I was 0.9% which was quite close. I am not complaining but I would have loved those prize money. My friend got $200 or$250 in total in the last 4 or 5 years he got prize money. I envy his natural talent. He also got scholarship for Sydney University's Gifted and Talented program so he didn't have to pay when I and my friends had to pay like $200 even if we successfully beat the 90% of the applicants. 6. Re: Westpac Maths Comp! Don't worry about the competitions overall, I have never got a distinction and I'm rank 6 in maths. 7. Re: Westpac Maths Comp! hey people, I know this thread is kinda old but yeah, the maths comp is like on the 2nd week of term 3 which is almost coming. I just want to ask, how do you solve the last problems? has anyoe ever got them right before? 8. Re: Westpac Maths Comp! Originally Posted by nerdsforever hey people, I know this thread is kinda old but yeah, the maths comp is like on the 2nd week of term 3 which is almost coming. I just want to ask, how do you solve the last problems? has anyoe ever got them right before? hey nerdsforever, yeah, this thread might be old but I was thinking of exactly the same thing! Like all the questions from like question 25-30, these ones from the Westpac Maths Comp seriously tend to be very hard and are often not seen in the appropriate year's syllabus. The question is: How do you get accustomed to these type of questions and are able to solve them if they require the maths skills often needed 1 year up than your own. (E.g. Yr 10 skills needed in Yr 9 Westpac Maths Comp) 9. Re: Westpac Maths Comp! Originally Posted by lookoutastroboy hey nerdsforever, yeah, this thread might be old but I was thinking of exactly the same thing! Like all the questions from like question 25-30, these ones from the Westpac Maths Comp seriously tend to be very hard and are often not seen in the appropriate year's syllabus. The question is: How do you get accustomed to these type of questions and are able to solve them if they require the maths skills often needed 1 year up than your own. (E.g. Yr 10 skills needed in Yr 9 Westpac Maths Comp) lol First few questions seem to be easy as we have usually learnt about that stuff before, but OMG what on earth is with the last questions! my mum reckons there is some formula to solving the last questions. And for the questions where you have to look at numbers say from 0 to 2000 or something, one friend told me you only look at the first ten numbers to find a pattern, and it will apply to the rest. I was like wtf? I usually just guess all the last questions. or maybe looking through a year 11 textbook might help. If there has been anybody who knows how to solve these ridiculous questions, please ... what do you do and how do you solve them? 10. Re: Westpac Maths Comp! yeah..you cant really study for these tests.. i for like 12% in year 7 1% in year 8 then back up to 8% in yr 9.. quite a big range.. just have to be prepared to answer questions that are designed to really challenge 11. Re: Westpac Maths Comp! Originally Posted by nerdsforever ... maybe looking through a year 11 textbook might help I can garentee this will not work, being in year 9 and learning the year 11 ext 1 material i can tell you, no amount of high school math can help you. These questions are about creativity and thought, its really about developing new math. Finding patterns is a big factor, on some of the questions you can ask yourself smaller questions and find a pattern then just extrapolate. 12. Re: Westpac Maths Comp! My results are Year 7 - HD Year 8 - D Year 9 - HD 13. Re: Westpac Maths Comp! Originally Posted by kurt.physics I can garentee this will not work, being in year 9 and learning the year 11 ext 1 material i can tell you, no amount of high school math can help you. These questions are about creativity and thought, its really about developing new math. Finding patterns is a big factor, on some of the questions you can ask yourself smaller questions and find a pattern then just extrapolate. What he said. 14. Re: Westpac Maths Comp! The AMC does not require too much creativity compared to some competitions. Infact i have never seen a question which requires the need to make up new methods. The last few questions can be very very very easy.....looking at intermediate last year the final was probably the hardest and even then converting the system to base 7 was easily done. 15. Re: Westpac Maths Comp! Originally Posted by Aznmichael92 My results are Year 7 - HD Year 8 - D Year 9 - HD omgsh. =O same. and then I got a distinction in yr 10 ... hoping for a High d this year. ^____^ or better. >:] 16. Re: Westpac Maths Comp! Originally Posted by lyounamu I have achieved several High Distinctions in the last 2 years I have taken this test. You cannot study for these exams. However, you can purchase some books (past papers) to try some questions that you can expect from the competition. My friend who got Prize Money every year in the last 5 years ($50 and he was damn close to getting picked for state & national) never studied for it. He was just naturally talented.

You don't have to perform well in this competition. There are not many gains from this unless you get picked for national team or state team.

17. Re: Westpac Maths Comp!

Originally Posted by lpodnano
nah there are many people who do way better than me...namely my friend at school who has been winning prize money for the lat 4 years =)

he was placed 0.2% of the state/nation/or wherever that does Westpac Com! lol

18. Re: Westpac Maths Comp!

Originally Posted by lyounamu
nah there are many people who do way better than me...namely my friend at school who has been winning prize money for the lat 4 years =)

he was placed 0.2% of the state/nation/or wherever that does Westpac Com! lol
you just get those people that have a natural affinity for these kinds of questions. I only ever got a HD in yr 7 and that was because the very little algebra i learnt in yr 7 was able to be applied easily. Other than just D after D haha.
In girra, two people got prizes from my yr last yr. One just has one of the greatest minds amongst our cohort to reason VERY FAST and work out methods to do things. The other however, aint as bright in school tests but his mind is more catered towards those harder problem solving questions.

19. Re: Westpac Maths Comp!

I still can't do last year's Question 30 of the AMC Intermediate Division, when I was in year 9. Can anyone land a hand?

The question is:

All the vertices of a 15-gon, not necessarily regular, lie on the circumference of a circle and the centre of this circle is inside the 15-gon. What is the largest possible number of obtuse-angled triangles where the vertices of each triangle are vertices of the 15-gon?

20. Re: Westpac Maths Comp!

Originally Posted by Omnipotence
I still can't do last year's Question 30 of the AMC Intermediate Division, when I was in year 9. Can anyone land a hand?

The question is:

All the vertices of a 15-gon, not necessarily regular, lie on the circumference of a circle and the centre of this circle is inside the 15-gon. What is the largest possible number of obtuse-angled triangles where the vertices of each triangle are vertices of the 15-gon?
The problem states that "the centre of the circle is inside the 15-gon". Therefore all the vertices of the 15-gon cannot lie in one semicircle (this is because the centre of the circle would be either on a side of the 15-gon or not be in or on it at all). Furthermore, an acute angled triangle is formed if any three points on a circle do not coinside in one semicircle, and an obtuse angled triangle is formed when any three points all coinside in a semicircle.

Remember we are trying to find the largest possible number of obtuse angled triangles formed, so we are trying to exclude the least amount of acute angled triangles possible. So consider all the vertices of the 15-gon on the semicircle (and for simplicity let two adjacent vertices lie on the diameter of the circle; ie the "base" of the semicircle).

Move just one of the vertices [of the 15-gon] which lie on the diameter out of the semicircle. Then any acute angled triangle formed will only be made with that vertex, the vertex on the diameter (ie the one we didn't move), and any other vertex in the 15-gon.

So with 2 vertices already chosen, this leaves us with 13 other vertices to choose from in order to make the acute angled triangle.

So we conclude that the minimum number of acute angled triangles formed is 13. So now we must find the maximum possible number of obtuse triangles formed.

To form a triangle in the 15-gon, we can choose any combination of 3 vertices. So there are:

$\binom{15}{3} = 455$

Thus there are 455 triangles that can be formed in the 15-gon.

Since the minimal number of acute angled triangles that can be formed is 13, then the maximum number of obtuse triangles that can be made is 455 - 13 = 442.

So the answer is 442.

21. Re: Westpac Maths Comp!

hey guys this comp was easy as
i alternated HDs and Prizes from year 7-12

22. Re: Westpac Maths Comp!

Originally Posted by u-borat
hey guys this comp was easy as
i alternated HDs and Prizes from year 7-12
Ive got HD/prize ever since year 7 with the prudence award (though it was called a special achievement award when i was in year 7) as well and i still wouldnt call this competition "easy" as such. A number of questions are simple but the contrary is also true, some are quite complex and can stun even the brightest among us. The last few questions ARE HARD!!
in any case, back to the question that started this thread. I would simply recommend that you not pay much attention to the westpac comp and focus on your other study. many of the questions you face in the westpac come from implicit skills you learn in your maths classes. but if your really keen than you can buy their books i guess. but is it really worth it?
Good luck to anyone who will be doing the wespac. (those who are in melbourne who really want to test their intelligence should ask their teachers about the melbourne university maths competition) haha (now aint that a fun way to spend three hours "points out the saturated sarcasm")

23. Re: Westpac Maths Comp!

Also, just a tip for this years Westpac Maths comp. It is useful to know important facts about the number that is the year in which the paper is set ie 2009. It is useful to know about the number 2009 because Australian Mathematics Competitions will almost always have a question that has the year in it. The most important feature to know about a number is its prime factorization. The prime factorization of 2009 is:

$2009 = 7^2 \times 41$

So note that:

• 2009 is not a prime number
• 2009 is not a perfect square
• 2009 is not a perfect cube
• 2009 is only divisible by 7 and 41

This will help you alot when you get the question which has 2009 in it =)

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