2012
Tue
23
Oct

# GCE O Level Oct/Nov 2012 E-Maths 4016 Paper 1 Suggested Answers & Solutions

(35)
Posted at 11:53 pm

Act I, Scene 2
Miss Loi’s Temple, Courtyard

TWAAANG! …

The playing of her guzheng was interrupted by hurried footsteps.

[Enter CHIEF DISCIPLE]

The Chief Disciple of The Temple appeared and rushed forward to kneel on one knee before the High Priestess.

My High Priestess 教主! Please forgive me for my interruption! But the thousands on our Facebook Page are getting impatient!

She stopped mid-way through her slooooooow tune.

These days there’s no time to even sit down and play a song after a late, late joss sticks session on the eve of EMaths Paper 2.

Very well then …

Suddenly, she began to play her guzheng faster and faster …

twaaang! twaaang! twaaang! TWAANG! TWAANG! TWAANG!

… until the following shot out from within the strings on the musical instrument.

Click the button and grab it here!

Access it here if you’re having trouble accessing it on Facebook using your state-of-the-art smartphone

N.B. As usual, please, please leave a comment should you spot any mistake in the solution. As uttered by the High Priestess, she was still deep within a joss sticks session just an hour ago!

Next, she threw out another swarm of daggers …

Now for Paper 2: Here’s a list of possible topics that may appear for tomorrow’s Paper 2.

1. Algebra (changing the subject of a formula, simultaneous equations, completing the square)
2. Arithmetic (percentages, ratios, interest, money & hire purchase, speed etc. – may still appear even though P1 already contains some)
4. Trigonometry (three-dimensional problems, bearing, angles of elevation/depression etc.)
5. Probability
6. Statistics (cumulative frequency curve, box & whisker)
7. Mensuration
8. Geometry (properties of circles)
9. Coordinate geometry
10. Similarity & congruency
11. Graphs (incl. plotting)
12. Sets & Venn diagrams
13. Matrices
ALL THE BEST for EMATHS PAPER 2 & GANBATTE!

[EXEUNT]

### Revision Exercise

To show that you have understood what Miss Loi just taught you, you must:

1. Jason says

2012
Oct
24
Wed
12:42am

1

Hi Miss Loi !

5) Will i still get the mark for value of a = 2 if i did not give two ans a=2 and a=-2 and then reject a=-2?

12a) Is it ok if i put 161 1/3 cm as an exact ans?

14) For entire bearing qn, if i got my point P wrong for first part, would they accept (error carried forward) for part b and c? And still award marks?

Thanks for taking time to read!

• 2012
Oct
24
Wed
3:46am

1.1

@Jason: Q5) Normally marks will be deducted for that (especially in school exams) but since this only carries 1 mark, the best you can hope for is this 1 mark to be fully allocated towards your correct answer of a=2 and nothing else (depending on the mark scheme).

Q12a) No problemo.

Q14) Unlikely, as the wrong position of P will affect the final answers of (b) and (c) which carries only 1 mark each.

Don't dwell on these and time to focus on your Paper 2 instead.

2. Edison says

2012
Oct
24
Wed
8:18am

2

For Q22b) AB is an exact answer. Shouldnt the answer be AB = 11.4378782 ( 7 digits)?

• 2012
Oct
24
Wed
3:21pm

2.1

@Edison: This is something Miss Loi really doesn't like

Apparently all Casio/Sharp calculators used in the exam halls showed 11.4378782 which appears to be exact (since not all digits are used).

On the other hand, a check with online calculators (like one or this one, as well as the ones residing in your Windows or Mac will yield something like 11.43787820165426 ...

As such, it's doubtful that Cambridge really intends it to be this way so Miss Loi believes some leeway will be given accordingly - especially if you've stated that clearly it's meant to be exact or approximated.

3. Despeate Math-er says

2012
Oct
24
Wed
9:20am

3

Hi Miss Loi!! For question 15, I forgot to write the properties such as the angle at centre = 2 angles at Oce, but since they are all only 1 mark questions, do I still get the mark?

• 2012
Oct
24
Wed
3:32pm

3.1

Assuming you have the added security of your workings, it *shoooould* be fine in this particular case since the 1 mark involved would likely go towards the accuracy of your final answer, despite how yim chim your (well-meaning) school teacher used to mark your school exam paper.

Miss Loi though would still advocate students to always state the necessary properties in workings.

4. Tyler says

2012
Oct
24
Wed
9:29am

4

Is ratio allow to have decimal?

• 2012
Oct
24
Wed
3:34pm

4.1

@Tyler: Strictly speaking, ratios can contain decimals e.g. 1.5 : 1 but your final answer should be reduced to its simplest form i.e. all integers.

5. Stacey says

2012
Oct
24
Wed
10:21am

5

May I ask ,why is the question on radius of A which is 50% greater than radius of B is squared instead of being cubed when finding mass? And it is to find the ratio of these two unknowns

• 2012
Oct
24
Wed
2:11pm

5.1

@Stacey: For Q24(b): Putting all ongoing discussions trying to dissect the areas, volumes, materials, "air space", blah blah blah of the cylinders aside, to state it simply, we've already established the formula for mass in part(a)(i) as follows:

M = 45r²

which means that the mass of each cylinder is directly proportional to the square of its radius i.e. Mr²

6. Dudeism says

2012
Oct
24
Wed
5:38pm

6

Hi Ms Loi,

For paper 1, is it okay to leave decimal answers in 4 sig figure?

Thank you!

• 2012
Oct
25
Thu
4:25am

6.1

• exact (all decimal places must be present)
• in degrees (one decimal place)
• a currency (nearest cent)
• non-exact otherwise (3 sig fig)

These are stated in the instructions on the first page of your exam paper.

7. Clarence  says

2012
Oct
24
Wed
6:45pm

7

Hey Miss Loi,

For question 25(a), since they asked us to express 'as simply as possible', don't we have to extract out the common factors for the answers?

Or are both answers for 25(a)(i), (ii), (iii), accepted? I.e. extracted and not extracted.

Thank you!

Clarence

8. Denton  says

2012
Oct
24
Wed
7:24pm

8

For question 23 c, is it okay if I put 47.9 instead of the full thing?

• 2012
Oct
25
Thu
4:29am

8.1

@Denton: Since it's exact, you shouldn't decrease its accuracy by rounding it from 47.925 to 47.9 *wags finger*

9. Joel says

2012
Oct
24
Wed
8:22pm

9

For the bearing question in paper 1,if I did not put it in 1d.p. would we get penalised?

• 2012
Oct
25
Thu
4:45am

9.1

@Joel: The bearing in Q14(c) should not contain a decimal point in the first place since it's an exact measurement. Furthermore, this is consistent with the question's degree of accuracy since the given bearing (055°) contains no decimal place.

10. --- says

2012
Oct
24
Wed
11:27pm

10

For 25a, i take out the common factor and put it as the answer
Will i get full marks?

11. winnie says

2012
Oct
25
Thu
10:31am

11

Can the vectors be factorised?

12. asdfasf says

2012
Oct
25
Thu
12:00pm

12

Hi...if i never put curly line under vector, is -1 for presentation only right? or -3? D:

• 2012
Oct
26
Fri
6:47pm

12.1

@asdfasf: Miss Loi has always forewarned students before an exam that "You run the risk of getting your ENTIRE vectors question marked ZERO if you don't do this! It has happened before in some unforgiving schools" (source).

After the exam, however, Miss Loi will tend to say that you may NOT even lose a mark for this (esp as this is O Level not school exam) depending on whether this is condoned by the mark scheme - likely it'll be accepted since there are no other variable a or b to confuse things in your working.

13. Raymond says

2012
Oct
25
Thu
11:29pm

13

Hi! Can the statistic answer be 161(3sf)? cos I thought statistic answers should not leave in fraction? As in the case of the calculator too.

• 2012
Oct
26
Fri
6:52pm

13.1

@Raymond: For Q12(a), 163 (3sf) or 163⅓ is fine either way since it's after all a suitable estimate ^^

Which math guru told you that "statistic & calculator answers should not leave in fraction?"

14. Raymond says

2012
Oct
26
Fri
3:07pm

14

Hi sorry but 1 more question from me. If my answer for qn 17c is male but I got 19.4% due to misunderstanding of the qn, will I get 1 or 0 mark?

### 5 Reactions

1. Miss Loi tweeted

2012
Oct
23
Tue
4:05pm

15

Joss Sticks session ended really, really late tonight :/... http://t.co/t9abU6rc

2. Miss Loi tweeted

2012
Oct
23
Tue
4:07pm

16

#olevel #emaths paper 1 full suggested solutions: http://t.co/RN8iq4Hl Good luck for your #emath paper 2!

3. 2012
Oct
24
Wed
12:59am

17

Answers are out for maths paper 1! http://t.co/TYmL5iM4

4. 2012
Oct
24
Wed
1:21am

18

#olevel #emaths paper 1 full suggested solutions: http://t.co/RN8iq4Hl Good luck for your #emath paper 2!

5. Leon Goh tweeted

2012
Oct
24
Wed
11:01am
• ### Latest News

Semester II schedules for Secondary / A Level Maths & Science (Chemistry & Physics) are out! With new math slots! *holds breath*

Miss Loi's 2014 Maths Exam Papers are here! The 2014 exam papers (covering the new AMaths 4047 syllabus) are finally here!

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

• ### Study Room Access

• WP Cumulus Flash tag cloud by Roy Tanck and Luke Morton requires Flash Player 9 or better.

More Mathematical Topics →

• ### Greatest Chatterboxes

(of the Month)

1. None yet!
• ### Careers @Miss Loi’s Temple

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 23 years she has been a savior to countless students ... [read more]

• ### Gratitudes

I can see that she is more confident now, especially when she has been previously suffering from lack of confidence and kept on telling me that she "can't do it". Now she says "Yes! I can do it!". ... [read more]

Emily Chiu
Shi Hui's Mom