Post-UMAT 2018 Debrief Thread

[Trinhcent]

There were two ‘this is to that’ questions last year so maybe that’s why ruffle asked. But yeah definitely none this year

yea they made an appearance last year bahah, this year all dem x-types tho

 

[Lear]

One thing I've learnt is that never bet your money on what questions can come. ACER is completely unpredictable, e.g., the new style of questions this year about the pregnant mothers. It's best to prepare for ALL types of questions, and if that's not enough, move to a country where your future is determined by a lottery ticket. Bruhhhh...

I second this. ACER consistently out plays preparation companies. Some kids I know who were accustomed to ME section 3 questions really struggled with section 3 this year. Some of the questions had unfamiliar patterns which were actually pretty simple if you looked at the bigger picture but if you tried to think of it in a typical ME movement fashion you would find yourself lost.

If there is one thing I learnt from this year's umat it's that being open minded is CRITICAL. Do not rely on practice papers at all.

 

[Trinhcent]

I second this. ACER consistently out plays preparation companies. Some kids I know who were accustomed to ME section 3 questions really struggled with section 3 this year. Some of the questions had unfamiliar patterns which were actually pretty simple if you looked at the bigger picture but if you tried to think of it in a typical ME movement fashion you would find yourself lost.

If there is one thing I learnt from this year's umat it's that being open minded is CRITICAL. Do not rely on practice papers at all.

yea the skills were transferable, ACER always manages to present in different ways that make you think

 

[GooDLaD]

One thing I've learnt is that never bet your money on what questions can come. ACER is completely unpredictable, e.g., the new style of questions this year about the pregnant mothers. It's best to prepare for ALL types of questions, and if that's not enough, move to a country where your future is determined by a lottery ticket. Bruhhhh...

I won't be surprised if the next new questions are legit just a meme.
go ahead and analyse that!!!!

 

[jiaxing]

Re: question about mixing liquids of different densities.

Suppose that we're in the process of finding a solution and we have four liquids initially in the order below:
A
B
C
D

If we realise that the difference in P values between A and B is >2, we look at the densities of each liquid. Let's suppose that A is denser than B, so we move A down right?

B
A
C
D

Would you then compare A and C, as well? Or would you stick with the order above?

 

[PimpOfRivia]

Re: question about mixing liquids of different densities.

Suppose that we're in the process of finding a solution and we have four liquids initially in the order below:
A
B
C
D

If we realise that the difference in P values between A and B is >2, we look at the densities of each liquid. Let's suppose that A is denser than B, so we move A down right?

B
A
C
D

Would you then compare A and C, as well? Or would you stick with the order above?

The question explicitly stated that if two liquids which are in contact have an absolute p difference of 2 or more, they mix. So yeah, you would need to (then) compare A and C.

You apply rule 1 (density) and then Rule 2 (mixing).

A very nice way to approach this question was to draw two vertical parallel lines (like a cylinder/testube) and then draw horizontal lines that represents the layer of liquid added. The consecutive liquid layers, using this technique could be added above or below the previous one depending on the density - afterwards you apply rule 2.

 

[jiaxing]

The question explicitly stated that if two liquids which are in contact have an absolute p difference of 2 or more, they mix. So yeah, you would need to (then) compare A and C.

Rule 1 (density) and then Rule 2 (mixing)

Phew! I think it's implied that if one liquid moves up/down, you would need to compare two adjacent liquids again.

 

[Smelly Boy]

Phew! I think it's implied that if one liquid moves up/down, you would need to compare two adjacent liquids again.

Oops don’t think I considered that (once liquid moves up or down you need to compare adjacent liquids again) but I seem to have gotten same answers as everyone else did in this thread when ppl were discussing answers lolll

 

[PimpOfRivia]

Yeah hahaha Smelly Boy

 

[jiaxing]

Oops don’t think I considered that (once liquid moves up or down you need to compare adjacent liquids again) but I seem to have gotten same answers as everyone else did in this thread when ppl were discussing answers lolll

Tbh, I forgot the specific questions and corresponding answers. All I remember is the concept of the question. Nevertheless, my reasoning was that if the liquids re-adjust, you would compare the two new adjacent liquids to see if they mix or move up/down.

 

[Lear]

Wasn't one of the question where they gave us 4 liquids poured in a certain order? I think there was 4 but two of them mixed together. I think the question asked how many layers were there or something like how many coloured layers?

 

[jiaxing]

Wasn't one of the question where they gave us 4 liquids poured in a certain order? I think there was 4 but two of them mixed together. I think the question asked how many layers were there or something like how many coloured layers?

Yes, I got 3 for that question

 

[Lear]

Yes, I got 3 for that question

Yep same

 

[Smelly Boy]

Wasn't one of the question where they gave us 4 liquids poured in a certain order? I think there was 4 but two of them mixed together. I think the question asked how many layers were there or something like how many coloured layers?

O yessss and I rememebr the option I chose was that the added liquid would mix with the liquid layer third from the top. But I didn’t consider the densities so probably got this one wrong. Unless I’m lucky enough for the densities to work out so that my answer is correct. Doubt it thooooo.

 

[Lear]

I can't quite remember what I got for maximum amount of layers if A-(last letter) were poured in order.

 

[jiaxing]

Yep same

That would suggest that after a liquid moves up/down, you re-analysed the scenario to see if two adjacent liquids would mix or move order. I did that too

 

[Q3]

Does anyone else also worry they they will get less than 50 in section 3? I can count on one hand the number of section 3 questions I knew. The rest were a blind and or educated guess. I don't need high marks in section 3 but I do need to meet a threshold and I don't think that is happening.

 

[Trinhcent]

Wasn't one of the question where they gave us 4 liquids poured in a certain order? I think there was 4 but two of them mixed together. I think the question asked how many layers were there or something like how many coloured layers?

I definitely got 3 layers for this and i believe 2 coloured layers but my memory's shot

 

[Smelly Boy]

Does anyone else also worry they they will get less than 50 in section 3? I can count on one hand the number of section 3 questions I knew. The rest were a blind and or educated guess. I don't need high marks in section 3 but I do need to meet a threshold and I don't think that is happening.

We just need to wait and see what happens doooood. Sit tight and hope for the best

 

[Lear]

I can't quite remember what I got for maximum amount of layers if A-(last letter) were poured in order.

(yes I am replying to myself)
I think for this question I remember recognising that the liquids were poured in order starting from A. Also, I believe A either had the highest or lowest density and as you went down the column it (increased/decreased). I.e the list was sorted in order of density. From this I somehow recognised that any new liquid poured would sit either above or below the next one poured ( I can't remember if the density was decreasing down a column or increasing but I did use this for my answer) and thus if the consequent liquid did NOT mix any other liquid poured on top of that would effectively be shielded from mixing with the one below the liquid that did not mix with the bottom one. This probably doesn't make sense but ill explain it with an example. Take liquids A B C

A - P=3, Density = 0.5
B - P=7, Density = 0.34
C - P=4, Density = 0.2

Now if we poured from A B C in order, We know that A would sit at the bottom as it has the highest density. When we pour B it will NOT mix with A but sit above it. Next we pour C. If we had simply mixed A and C they would have mixed, however, since C is less dense than B, B will effectively shield C from mixing with A at the bottom (I remember the question mixing there was no turbulent mixing or something).
Thus, despite having two liquids that do mix together, we would still have three layers.

I believe this is the logic I used when answering the question about maximum possible layers.
Anyone else use this?