Australian Maths Competition (5 Viewers)

[Official]

Re: Australian Mathematics Competition

i did the intermediate paper today - felt quite good about it lol

i reckon:

1-10 =30 marks
11-20 = 40 marks
21-25 = 20 marks (stuffed one question, careless mistake)
26, 27, 28, 29 solved = 30 marks

Total = 120 marks

for 26-29, were the answers 419, 578, 31, 231?

That'll get you first in the state. And possibly Australia.

 

[khorne]

Re: Australian Mathematics Competition

Just out of curiosity, how did everyone else do the ascending question (disregarding my cheap method). I thought you could go through a series of eliminations, but is there any other way?

 

[lolokay]

Re: Australian Mathematics Competition

i figured it out with elimination (starting with the last digit)

(btw, i didn't actually sit the test)

 

[kurt.physics]

Re: Australian Mathematics Competition

i did the intermediate paper today - felt quite good about it lol

i reckon:

1-10 =30 marks
11-20 = 40 marks
21-25 = 20 marks (stuffed one question, careless mistake)
26, 27, 28, 29 solved = 30 marks

Total = 120 marks

for 26-29, were the answers 419, 578, 31, 231?

The answers for 26-29 that you put down is what I got also. Also, which question was the one you stuffed up?

 

[Petyo]

Re: Australian Mathematics Competition

i figured it out with elimination (starting with the last digit)

(btw, i didn't actually sit the test)

yea that's what I did. I got 578 for that one @@

 

[Petyo]

Re: Australian Mathematics Competition

Did anyone figure out how to solve the last question??

 

[Timothy.Siu]

Re: Australian Mathematics Competition

anyone know to answers to 28,29,30 in senior?

 

[Iruka]

Re: Australian Mathematics Competition

My solution to Q30 in the senior division.

View attachment 18994

 

[xV1P3R]

Re: Australian Mathematics Competition

What did people get for the octahedron one? The d^2 one, I got 81.

What I did was squash the 3D figure into a plane and did the straight line distance from one centre to the other. Can anyone check if this is right?

 

[Official]

Re: Australian Mathematics Competition

What did people get for the octahedron one? The d^2 one, I got 81.

What I did was squash the 3D figure into a plane and did the straight line distance from one centre to the other. Can anyone check if this is right?

Apparently this one is 48

 

[nerdsforever]

Re: Australian Mathematics Competition

Also for Q15 the eyebrow number one, what did you all get? I got A...it was a 50% guess.
and for the traitor question, what is the answer? I was pretty sure i knew the right answer before I started checking it and went around in circles!

yeah.

the second and fourth number can be either:

3 and 5
4 and 5

3 and 5: 2 arrangements
the reverse of that = 2 arrangements
4 and 5: 3! = 6
the reverse of that = 3! = 6

adding together = 6 + 6 + 2 + 2 = 16

the answer is A

 

[lolokay]

Re: Australian Mathematics Competition

Apparently this one is 48

I actually get 84 for this one *

my solution:

Spoiler

if you unfold the 3D shape into its net (only the side facing you, and with the dots) then you get a sort of double rhombus. the shortest distance is then found simply by connecting the two points with a line, and finding its length with pythagoras

 

[nerdsforever]

Re: Australian Mathematics Competition

From most of the responses on the BOS, I assume that most people found the test alright. I'm thinking that the cut offs for distinction and high distinction will be very high

 

[Official]

Re: Australian Mathematics Competition

I reckon Distinction = 60
High Distinction = 70
Prize = 80 ish?
hopefully

 

[mastermind666]

Re: Australian Mathematics Competition

I reckon Distinction = 60
High Distinction = 70
Prize = 80 ish?
hopefully

I reckon D >60, HD>85, P>100, the intermediate ppr wasnt that hard, considering a third of my yr level at school got out 1 or 2 of the last 5

the question i stuffed up? that plindrome one

proved that the middle digits had to be divisible by 7, and i forgot to take the case where the middle digits are 00, and got 9 nstead of 18 grrrrrr

 

[nerdsforever]

Re: Australian Mathematics Competition

for the divisible by 7 one, I basically listed all the two digit numbers from 11 - 99 inclusive, and then reversed them.

e.g.
1111
1221
1331
1441
1551
etc

I know that the answer is definitely more than 15.

 

[nerdsforever]

Re: Australian Mathematics Competition

what was the answer to the question on the clock face and the size of the acute angle?
what about the one on the positive fraction + reciprocal = x/60??
and the one on the four cicles drawn with centres at the four vertices of a square?

 

[Official]

Re: Australian Mathematics Competition

I reckon D >60, HD>85, P>100, the intermediate ppr wasnt that hard, considering a third of my yr level at school got out 1 or 2 of the last 5

the question i stuffed up? that plindrome one

proved that the middle digits had to be divisible by 7, and i forgot to take the case where the middle digits are 00, and got 9 nstead of 18 grrrrrr

Yeh but I did Senior.

 

[Official]

Re: Australian Mathematics Competition

for the divisible by 7 one, I basically listed all the two digit numbers from 11 - 99 inclusive, and then reversed them.

e.g.
1111
1221
1331
1441
1551
etc

I know that the answer is definitely more than 15.

The answer to this is 18.
1001 and 1771 are divisible by 7.
2001 and 2771 are divisible by 7.
3001 and 3771 are divisible by 7.
So on...
Answer becomes 18 (D)

what was the answer to the question on the clock face and the size of the acute angle?
what about the one on the positive fraction + reciprocal = x/60??
and the one on the four cicles drawn with centres at the four vertices of a square?

Clock face is 45 degrees.
Positive fraction + reciprocal = x/60 is 4, Gurmies has the answer somewhere.
Last question, dunno

 

[lolokay]

Re: Australian Mathematics Competition

for the overlapping circles one, i drew, separately, two circles overlapping at opposite corners, and two circles overlapping at adjacent corner. from these, i found the values of different areas of the shapes in the four overlapping circles, and could then deduce the area of the section overlapped by all 4