Westpac Maths Competition (2 Viewers)

[robot rabbit]

The no calculator rule makes me cry year after year.

 

[dux&src]

Hahaha. I never get distinctions lol. I always go really bad... well not really bad but a low/medium credit, which I suppose it okay considering the difficulty of the test! I can tell that I got soo much wrong and I had trouble using my head for factors, dividing, prime numbers (not too bad lol) etc.

GAYEST TEST EVER!

Haha well they actually determine your certificate by you percentile in the state.

 

[Aquawhite]

Haha well they actually determine your certificate by you percentile in the state.

Yes, I understand that. Lol.

hehe.

 

[dux&src]

The no calculator rule makes me cry year after year.

But, really you don't actually need a calculator to do the competition.

and lol it's almost impossible to get zero unless you left everything blank.

 

[robot rabbit]

But, really you don't actually need a calculator to do the competition.

and lol it's almost impossible to get zero unless you left everything blank.

I know one person whom randomly coloured in the bubbles.

I tend to make silly mistakes and i have become very dependent on the calculator lately. So if the calculator's gone, the tears start to well up.

 

[Aquawhite]

But, really you don't actually need a calculator to do the competition.

and lol it's almost impossible to get zero unless you left everything blank.

My head hurted having to do all the questions without a calculator. e.g. i could have used trig in a few of the triangle questions.... should have read my book at home it has every angle for sin cos and tan. Lol. Would have got a general idea of how the numbers work.

AND I never learnt how to do long division so I was totally screwed.... I did do the short division though.. I managed, just took a very long time.

 

[dux&src]

I know one person whom randomly coloured in the bubbles.

I tend to make silly mistakes and i have become very dependent on the calculator lately. So if the calculator's gone, the tears start to well up.

She did, bhahah
remember to tell me what she got. i would lol if she got a credit or higher haha

Oh, awww. But i remember my teacher saying that back in her days there were not many calculator exams, mostly using the head. :jaw:

Now what was the question number of that farmer question. I'm gonna wait till we get the results to see if i got that one right by guessing.

 

[robot rabbit]

It was number 21, the first of the 5 mark questions i think.

 

[jordankuai22]

couldnt complete last 3 questions :S

 

[dux&src]

It was number 21, the first of the 5 mark questions i think.

Oh cool thank you, comeon 1/5 chance of getting it right.

 

[kurt.physics]

When do we get the results back?

 

[Aquawhite]

When do we get the results back?

Because these things take a while to go through the computer and be checked by people, I imagine a long time. They are also very slow to post them off....

It's annoying waiting for them. So i lose intrest and randomly look surprised when they come back... Wow, they came back this time.

 

[dux&src]

When do we get the results back?

You get it early term 4. as always.

 

[robot rabbit]

Also the proximity of the school has an impact upon the delivery time.

 

[kurt.physics]

At least the questions were fairly interesting. The only AMC test i could practice on was the 2002 one, and i can say, this one is faaarrrr more interesting than 2002's one.

I am just curious, what method did everyone use for question 6) Four consective odd integers add up to 48. What is the largest of these numbers?

 

[robot rabbit]

Elimination method for question 6.

 

[Aquawhite]

At least the questions were fairly interesting. The only AMC test i could practice on was the 2002 one, and i can say, this one is faaarrrr more interesting than 2002's one.

I am just curious, what method did everyone use for question 6) Four consective odd integers add up to 48. What is the largest of these numbers?

It was much faster to use guess and check than formulating an equation. Use the options there are you can't really go wrong. That one was pretty easy. There was no need to have like x-6 < x-4 < x-2 < x blah blah blah. That would be ridiculous lol. No time.

 

[kurt.physics]

It was much faster to use guess and check than formulating an equation. Use the options there are you can't really go wrong. That one was pretty easy. There was no need to have like x-6 < x-4 < x-2 < x blah blah blah. That would be ridiculous lol. No time.

You didnt have to do it that way, there is a more easier clean 'proof'. This is what i used, i was just curious if many other people used/though of it to.


Let the first odd integer be 2n + 1 , where n is any integer

the next 3 consecutive integers will be

2n + 3
2n + 5
2n + 7

If we add 2n + 1, 2n + 3, 2n + 5, 2n +7 all together we get

2n + 2n + 2n + 2n + 1 + 3 + 5 + 7

this equals 48, there fore

2n + 2n + 2n + 2n + 1 + 3 + 5 + 7 = 48

8n + 16 = 48
8n = 32
n = 4

so the largest of these numbers is 2n + 7

therefore

2(4) + 7 = 15

thus 15 is the largest of these numbers.

 

[kurt.physics]

Just looking over this, yes, its quite long, but in a sense its not. It took me 1 minute in the test to think this up and calculate, so its probably easier than trial and error.

For example, this method of not guessing would have been particularly useful for Q18) A number is less than 2008. It is odd, it leaves a remainder of 2 when divided by 3 and a remainder of 4 when divided by 5. What is the sum of the digits of the largest such number?

EDIT: Did anyone manage to answer this?

 

[rolror88]

Yea.. I did. I just did odd numbers which ended in 9, starting from 1999. Then divided them by 3.. to find the answer. Didn't take long, it was like the 4th number down, or something like that.

Was there another way to work it out? ie Algebra?

WIth Q6.. I just used basic algebra.