exam 2 thoughts + answers, applying sticky

[kjg]

thats what i got

and got -.09 for residual


oh sweet lord please give me one correct answer from the whole exam

[maxleng]

fuck must have skipped over it asking for year 2000, just assumed that the previous answer (2010) carried on

[*insert witty name here*]

LOL come on..someone must have done sequences and series?

[blingerz]

hey i fink it was 2010, cos they gave the actual value for 2010 didnt they? or was it 2000 >_<
i got -0.22

[M575]

also for the geometry, last question: i got (1/4)^3 =  1/64

which one is correct o_O

and how did you get 37/64....

the answer is actually 37/64 because

from the previous question:
ratio of length between the two pyramids= 3:4
ratio of volume between the two pyramids= (3)^3 : (4)^3
= 27: 64

therefore, the ratio of the volume of the remaining block to the volume of the pyramid is (64-27) / 64 = 37/64

Ok, I got 63/64 AKA, 98%. let me show you my logic. the previous question asked what fraction of the pyramid is just the big one.. this would make it 3/4 (yes, I wrote 1/4 aswell.. first but re-read the question a few times and changed it..) thus.. 3/4 is big 1/4 is small. then comes the next question (I think they purposly did this to trick people) you were supposed to use 1:4 as the ratio. as, 3/4 is big and 1/4 is little. So 1 : 4 is little. then from there..

1^3 : 4^3

1 : 64

x : 7168

112 : 7168 and work from there.. now, at first I thought "no way!" but then, think about it, the tip of the pyramid can't be almost half of the whole thing.. so that's how I got 63/64 lol.. and I know a few others who did too, and they are smart peeps!

[M575]

oh, and I also got -.09 and double checked it

[kjg]

they asked 2010

there we go, i at least got 1/60

[maxleng]

oh, and I also got -.09 and double checked it

-.09 is right if it was 2000, but i did it as 2010, are u saying you double checked it was 2000 or u double checked your answer in the exam?

[*insert witty name here*]

Ok, I got 63/64 AKA, 98%. let me show you my logic. the previous question asked what fraction of the pyramid is just the big one.. this would make it 3/4 (yes, I wrote 1/4 aswell.. first but re-read the question a few times and changed it..) thus.. 3/4 is big 1/4 is small. then comes the next question (I think they purposly did this to trick people) you were supposed to use 1:4 as the ratio. as, 3/4 is big and 1/4 is little. So 1 : 4 is little. then from there..

1^3 : 4^3

1 : 64

x : 7168

112 : 7168 and work from there.. now, at first I thought "no way!" but then, think about it, the tip of the pyramid can't be almost half of the whole thing.. so that's how I got 63/64 lol.. and I know a few others who did too, and they are smart peeps!

HAHA, okay look i understand your process of thinking..however, i still maintain that is incorrect.
remember, when you are finding a ratio between objects, they must be similar. that trapezoidal prism thing [i.e. the left over bit of the pyramid] is dissimilar to the pyramid..for obvious reasons :]
and the volume is incomparable.

i'm sure your friends are smart..but i'll take my teachers confirmation =p
anyway, i sort of use the techniques i use in specialist maths and those that i learnt in methods last year..and apply them to further

[maxleng]

Ok, I got 63/64 AKA, 98%. let me show you my logic. the previous question asked what fraction of the pyramid is just the big one.. this would make it 3/4 (yes, I wrote 1/4 aswell.. first but re-read the question a few times and changed it..) thus.. 3/4 is big 1/4 is small. then comes the next question (I think they purposly did this to trick people) you were supposed to use 1:4 as the ratio. as, 3/4 is big and 1/4 is little. So 1 : 4 is little. then from there..

1^3 : 4^3

1 : 64

x : 7168

112 : 7168 and work from there.. now, at first I thought "no way!" but then, think about it, the tip of the pyramid can't be almost half of the whole thing.. so that's how I got 63/64 lol.. and I know a few others who did too, and they are smart peeps!

HAHA, okay look i understand your process of thinking..however, i still maintain that is incorrect.
remember, when you are finding a ratio between objects, they must be similar. that trapezoidal prism thing [i.e. the left over bit of the pyramid] is dissimilar to the pyramid..for obvious reasons :]
and the volume is incomparable.

i'm sure your friends are smart..but i'll take my teachers confirmation =p
anyway, i sort of use the techniques i use in specialist maths and those that i learnt in methods last year..and apply them to further

can you tell me if what i did was right/wrong:

i) i got the ratio 3:4 and then cubed this for the volume ratio which gave 27:64 and isnt that the answer? (i assumed as it was only 1 mark)

ii) Did part 2 ask for the exact volume? becuase people have been giving ratio's( i thought it was actual volume..)
Volume of bottom = Total volume - Top volume

total was 7168 or something, and then top i used the volume ratio and divided 7168 by it since we knew the height of the top being removed and the height of the whole thing..

which game me the volume of the 'bottom' as : 4144m^3

[*insert witty name here*]

can you tell me if what i did was right/wrong:

i) i got the ratio 3:4 and then cubed this for the volume ratio which gave 27:64 and isnt that the answer? (i assumed as it was only 1 mark)

ii) Did part 2 ask for the exact volume? becuase people have been giving ratio's( i thought it was actual volume..)
Volume of bottom = Total volume - Top volume

total was 7168 or something, and then top i used the volume ratio and divided 7168 by it since we knew the height of the top being removed and the height of the whole thing..

which game me the volume of the 'bottom' as : 4144m^3

okay for q4 a) the question asked for the ratio of the HEIGHTS between the small pyramid i.e. the part that got chopped off and the whole pyramid before any changes. so the answer to a was just 24: 32 = 3:4

the second part b) asked for the ratio between the VOLUME of the part that was left over and to the whole pyramid before any changes

and to do that, you had to find the ratio between the volume of the little pyramid and that of the big

which was 27: 64 as we said. therefore, the remaining volume which is 64-27 = 37 is the volume of the left over section. so the ratio is 34: 64

hope that is of help =]

[M575]

I am positive that for that core question, the answer is -.09. also, for the ratio question, I am certain that it was asking how much is left, ie, 1/4 instead of 3/4. Like I said, I wrote down 1/4 first, but then re did it and re read the question, using my finger :p lol.. and changed it to 3/4. it was one of the last questions right.. ?

[joechan521]

my solutions so far so good ^^

[AhaShake]

for that proportion matrices question i wrote 50%... will that mean i wont get the marks? i looked at the vcaa matrices supplement thing and they had one column that said proportions and then had percentages, but i dont know.
anyone have any idea? it could be the only mark i lose...

[dxb]

year was 2010

It was both, their were 2 questions, one asked for the 2010 value and then another question below it asked for the 2000 value. Thats all i can remember tho,....