Message #1: Complimentary spa session for all new treatment package sign-ups at ABC Beauty & Slimming Centre!

Message #2: Bring a friend and get a free 1 month gym membership at XYZ Fitness!

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*BIG WHACK ON THE HELMET POOOOOONG!!!*

Can you please skip all the spam and read only messages from the frontline for today’s O Level EMaths Paper 2????!!!!!!!

SORRY MDM! Here are the relevant messages!

2day’s paper so easy! 😉 haha. Can get A1 🙂

What we went through yesterday came out! I dunno can get A or B but I know I improved! Thx!

I found this paper very manageable too!

Nice I can do 🙂

Oh crap I lost 6 marks liao! Miss Loi: Aiyooh …

It appears our troops have fought well today, and our Enemy seems to be retreating. However, the papers seem too easy, and I now have to brace myself for the perennial “how many marks to get A1?” question.

Listen up Sergeant Loi! For those whose mathematical journey has ended, send them my ugly handwriting scribblings and ask them to check for mistakes!

Oops! Before the lot of you start complaining, Miss Loi is amending the vertical m-axis of the graph in Q9 now - which should be 2 ≤ m ≤ 6 😛 [Ok, amended]

@Miss Loi: ii click on the link u give and then click emath paper 2 solution ... but the window went blank.... and it says the loading is done >.< iim sorry ii new here. so dunno how to use it.

@Miss Loi: vector, for some reason I got DB = (1 5) and I said DB perpendicular to DE since DB parallel to OE. The other 'fact' was |DB| and |DE| are the same cos both (1 5). Must've been blind.

Surface area. I got the slant height of the pyramid as sqrt (10^2 + 12^2). I did not recognise the 10 as the whole length, and what was needed was only half of it. 🙁

In fact the first attempt I got that funny area of triangle already, and forgot to multiply that by 4.

question 5 was tricky haha. a lot of people from my school thought angle CXD was the interior angle. i got tricked initially as well, but i'm glad i spotted the mistake.

I made lots of careless mistakes. Yes and I got tricked by question 5 🙁 6marks gone... I've checked the answers, I got around 85 for paper 2 and 70+ for paper... Can I still get my A1?

... estimating A1 to be 155/180, A2 to be 145/180, B3 to be 135/180 and B4 to be 125/180.

you've just made it! *throws confetti*

Note: The above is pure speculation and not to be taken seriously as the actual grade cut-offs, and furthermore Miss Loi has always advocated aiming for "85% for A-Maths and 90% for E-Maths to get an A1!", simply to buffer the possibility of unknown/hidden marks lost through backstabbing by the markers workings, significant figures etc.

Yo, what is the estimated bell curve for this paper...i have checked your solution..I got estimated 95% for paper 2 and 85% so is my probability of getting an a 2 high? i hope can get an a 2 at least...a1 hmmm Doubth so...

Sorry i have to bother you with another question. For paper 2 the question on the tunnel that one. What will i get if my part a the answer oso wrong but if my method is correct for parts b and c. And i heard from my friend who took last years o level that the mark to get an a1 was 80. Can this be true?

@cheryl: Moved your P2 question to this Emaths P2 post.

The Q8 tunnel question requires the correct value of the reflex angle POQ obtained in (i) to sub into (1/2)ab sinC for the area of triangle in (ii), as well as the (1/2)r^{2}θ for the area of the major segment in (iii).

And with just 2 marks on offer for each part, you're probably looking at ≤ 1 mark as M marks for each part provided you've written out your steps and formulae clearly.

Miss Loi has received a couple of emails from some who were caught out by the sneaky polygonic parasite X in Q5. One of which

Ive seen ur emaths paper 2 solutions however i do not agree to the answer for question 5 whole question because to my view.. 360 divide by number of sides 15 gives u the exterior angle but they are asking for the angle in the isosceles triangle so u have to get 180 minus away the ext angle to give u Interior angle 156 and den 180 minus int angle and divide by 2 for the 2 identical angle which will end up in 12 degrees thats my answer ,could u pls check the question again? Or did i mistaken the question.

Thank you

To illustrate further, what the above student (and most others who had been tricked by the nasty parasite X) had calculated is as follows:

However, as depicted in this earlier comment, Point X and the two lines CX and XD (the parts labeled in red below) are never part of the 15-sided polygon ABCDEF ... (notice the question didn't label the polygon ABCXDEF ..., and the absence of the equivalent signs || on CX and XD)

Hence ∠XCD is already an exterior angle of the polygon, and you can proceed to obtain ∠CXD via interior angles of isosceles triangle ΔXCD as shown below.

Sadly, the number of Q5 victims seems to have hit holocaustic proportions 🙁

@liliting: Come ... come ... please cool down and let Miss Loi give you a big virtual hug.

While no one on this planet (apart from the faceless agents in the shady organization known as the SEAB) will know with 100% certainty the cut-off mark for each grade, it's time to do some selective reading and reproduce some quotes from that SGClub forum thread where you probably came from 😀

Don't worry so much for moderation is more to help rather than drag students down. So long as u know u've done ur best, I figure that it is enough no matter the grades.

According to my teacher,

A1 and A2 gets moderated more.

B3 - F9 gets moderated too, but lesser.

IMO if you got 60+ you will never get C as every year moe gave large percentage of candidates get b3. C5-6 is generally given to punish those who didnt study and got 40-50 but give some face to you. My teacher said barely no one got D7 or E8/F9 unless you dont know any shit or just slept for the whole paper. So if your friend got C6 in actual fact they have failed the paper.

... focus on other subjects. the previous paper has ended. your fate is sealed the moment you finished your paper, collected back and send to Cambridge ... don't worry too much. if you know you have tried your best, done your best, then there is nothing to worry. why make yourself worry too much about such things when you can spend more time and brain power to concentrate on other subjects?

Now what you guys should do is: 1) Stay optimistic 2) Focus on other subjects

*squeeze squeeze liliting a little tighter*

Now can you please go and focus on your remaining papers and make sure you do well for them? GANBATTE!

@Dean: No they have equal weightage.i Ms loi: do you think this years bell curve will be lower than last year considering the tricky questions and the probability question in paper 1

Cuz the last answer i got was 3 hours , 39 mins , 30s . instead of yours : 3 hours , 39 mins , 33s

The instructions regarding degree of accuracy is a little brief on this year's question paper, but the following para remains on page 2 of SEAB's syllabus document:

Unless stated otherwise within a question, three-figure accuracy will be required for answers. This means that four-figure accuracy should be shown throughout the working, including cases where answers are used in subsequent parts of the question. Premature approximation will be penalised, where appropriate. Angles in degrees should be given to one decimal place.

In this case, Q6(d) specifically asked us to give the answer correct to three decimal places, which is 11.478 km/h.

While Miss Loi really, really doesn't enjoy interpreting the intention of such statements in a subject like Mathematics, using 11.48 in part (e) is akin to a premature approximation of 11.478 (even though it's 4 sig. fig.) when it's more accurate to use an accuracy of at least an order higher i.e. 11.4777 (4 d. p.) in this case.

As Miss Loi has said before, it's always dangerous to assume that a less accurate answer is a better answer, so always err on the side of more d.p./sig. fig. within your workings when in doubt.

Hope that Cambridge markers will be lenient on this though 🙁

* Please refer to the relevant Ten-Year Series for the questions of these suggested solutions.

About Miss Loi

Miss Loi is a full-time private tutor in Singapore specializing in O-Level Maths tuition. Her life’s calling is to eradicate the terrifying LMBFH Syndrome off the face of this planet. For over years she has been a savior to countless students … [read more]

Gratitudes

I learnt that you took individual care and concern on every one of your students … [read more]

## 35 Comments

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Oops! Before the lot of you start complaining, Miss Loi is amending the vertical

m-axis of the graph in Q9 now - which should be 2 ≤m≤ 6 😛 [Ok, amended]曜

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@Miss Loi: hmm how to see the answer? ii press the worksheet . so small ? ii cant see . and onli one page o.o?

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@winnie: Ummmmmmmm ... did you *click*

onthe worksheet itself?Anyway you may view the full set of solutions (including those from past years) here.

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@Miss Loi: ii click on the link u give and then click emath paper 2 solution ... but the window went blank.... and it says the loading is done >.< iim sorry ii new here. so dunno how to use it.

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@winnie: Is it only Emaths Paper 2 that you were unable to view? Are you able to view the solutions for the rest of the papers?

Alternatively, could you try clicking on the link below (or right-click and select 'save as') and see if you can open it?

https://www.exampaper.com.sg/blog/wp-content/uploads/gce-o-level-2010-emaths-4016-paper-2-solutions.pdf

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oh no I made 2 mistakes 🙁

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@mathslover: Oh no where? Where?

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@Miss Loi: vector, for some reason I got DB = (1 5) and I said DB perpendicular to DE since DB parallel to OE. The other 'fact' was |DB| and |DE| are the same cos both (1 5). Must've been blind.

Surface area. I got the slant height of the pyramid as sqrt (10^2 + 12^2). I did not recognise the 10 as the whole length, and what was needed was only half of it. 🙁

In fact the first attempt I got that funny area of triangle already, and forgot to multiply that by 4.

Sigh.

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question 5 was tricky haha. a lot of people from my school thought angle CXD was the interior angle. i got tricked initially as well, but i'm glad i spotted the mistake.

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@zette: Yes that sneaky little

Xreally settled down nicely and camouflaged itself well on the main polygon didn't it?It's like that polygon has got a parasite feeding on it or something 😛

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I made lots of careless mistakes. Yes and I got tricked by question 5 🙁 6marks gone...

I've checked the answers, I got around 85 for paper 2 and 70+ for paper... Can I still get my A1?

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@mathmathmath: Taking the worst case if you scored 70 for Paper 1, mathmathmath overall marks:

0.5 × (70/80 × 100%) + 0.5 × (85/100 × 100%) ≈ 86.3 (3 sig. fig.)

And according to The Seer this year

you've just made it! *throws confetti*

Note: The above is pure speculation and not to be taken seriously as the actual grade cut-offs, and furthermore Miss Loi has always advocated aiming for "85% for A-Maths and 90% for E-Maths to get an A1!", simply to buffer the possibility of unknown/hidden marks lost through

~~backstabbing by the markers~~workings, significant figures etc.曜

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@Miss Loi: i certainly hope that the results would come out as what the seer has predicted. haha

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The first fact for points DEB is that

1) Point E is the midpoint of D and B!

2) They all lie on the same line

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@Kelly: Yuppy yuppy yup 😀

Since

⇒

D,EandBare collinear (i.e. they all lie on a straight line)and since

⇒

Eis the mid-point ofDandB曜

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Yo, what is the estimated bell curve for this paper...i have checked your solution..I got estimated 95% for paper 2 and 85% so is my probability of getting an a 2 high?

i hope can get an a 2 at least...a1 hmmm Doubth so...

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@Lio: Aiyo ... Pro Lio, please see Miss Loi's workings in this comment.

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Sorry i have to bother you with another question. For paper 2 the question on the tunnel that one. What will i get if my part a the answer oso wrong but if my method is correct for parts b and c.

And i heard from my friend who took last years o level that the mark to get an a1 was 80. Can this be true?

曜

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@cheryl: Moved your P2 question to this Emaths P2 post.

The Q8 tunnel question requires the correct value of the reflex angle

POQobtained in (i) to sub into (1/2)absinCfor the area of triangle in (ii), as well as the (1/2)r^{2}θfor the area of the major segment in (iii).And with just 2 marks on offer for each part, you're probably looking at ≤ 1 mark as M marks for each part provided you've written out your steps and formulae clearly.

曜

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Miss Loi has received a couple of emails from some who were caught out by the sneaky polygonic parasite

Xin Q5. One of whichTo illustrate further, what the above student (and most others who had been tricked by the nasty parasite

X) had calculated is as follows:However, as depicted in this earlier comment, Point

Xand the two linesCXandXD(the parts labeled in red below) areneverpart of the 15-sided polygonABCDEF... (notice the question didn't label the polygonABCXDEF..., and the absence of the equivalent signs || onCXandXD)Hence ∠

XCDisalreadyan exterior angle of the polygon, and you can proceed to obtain ∠CXDvia interior angles of isosceles triangle ΔXCDas shown below.Sadly, the number of Q5 victims seems to have hit holocaustic proportions 🙁

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?????????????? anyone hav an idea c6 is it = 50 mark/?

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@liliting: Come ... come ... please cool down and let Miss Loi give you a big virtual hug.

While no one on this planet (apart from the faceless agents in the shady organization known as the SEAB) will know with 100% certainty the cut-off mark for each grade, it's time to do some selective reading and reproduce some quotes from that SGClub forum thread where you probably came from 😀

*squeeze squeeze

lilitinga little tighter*Now can you please go and focus on your remaining papers and make sure you do well for them?

GANBATTE!曜

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i got tricked by the polygon question!! so does that mean that i will get all wrong for that whole question? 🙁

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Does paper 1 weight higher than paper 2?

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@Dean: No they have equal weightage.i

Ms loi: do you think this years bell curve will be lower than last year considering the tricky questions and the probability question in paper 1

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@cheryl: I tot paper 1 weight heigher than paper 2 in maths but the other way wrong in amaths?

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@Dean: Actually Miss Loi thinks they both weigh about 100 grams each 😛

Okie okie jokes aside, hope the following will clear things up:

EMaths weightage: Paper 1 (50%), Paper 2 (50%)

[Source: Page 2 of SEAB 4016 syllabus doc]

AMaths weightage: Paper 1 (44%), Paper 2 (56%)

[Source: Page 3 of SEAB 4038 syllabus doc]

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@cheryl: See Miss Loi's reply here.

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After checking the answers for paper 2....I think my A1 or A2 would be gone. I might get a B3....oh god. -.-"

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Just dug out another email from the pile ...

The instructions regarding degree of accuracy is a little brief on this year's question paper, but the following para remains on page 2 of SEAB's syllabus document:

In this case, Q6(d) specifically asked us to give the answer correct to

three decimal places, which is 11.478 km/h.While Miss Loi really, really doesn't enjoy interpreting the intention of such statements in a subject like Mathematics, using 11.48 in part (e) is akin to a

premature approximationof 11.478 (even though it's 4 sig. fig.) when it's more accurate to use an accuracy of at least an order higher i.e. 11.4777 (4 d. p.) in this case.As Miss Loi has said before, it's always dangerous to assume that a less accurate answer is a better answer, so always err on the side of

mored.p./sig. fig. within your workings when in doubt.Hope that Cambridge markers will be lenient on this though 🙁

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do u hav paper 1 ans?

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@dabulot: Nah!

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Hi Ms Loi! The TYS answers says that Q10c (for the 2010 paper 2) is 7/295, but your (more trustworthy) answer says it's 7/590.

Can I confirm if it's an error with the TYS answer? Might have lost two marks in today's paper....BECAUSE I faithfully followed the TYS.

Irony much?

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@Kester Tay: That TYS of yours doesn't seem legit - see here.

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maths is hard....... 🙁