Welcome to O Level Halloween Week, where the 2014 batch of students are being “trick-or-treated” to one of the most evil O Level timetables in recent memory.

As The Temple is dark and empty of students (who are probably listening to some radio for their Listening Comprehension) as I speak, I managed to hop out of the fridge unnoticed to discover this set of worked solutions on my Mistress‘ desk.

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

As usual, please, please leave a comment should you spot any mistake in the solution.

Notes from my Mistress:

Before you ask questions like “I lost x marks in Paper 2, can I still get A1/A2/B3/B4/pass?” or “What is the cutoff for A1/A2/B3/B4/C5/C6/D7/E8/F9 this year?”, please understand that Miss Loi is NOT the Bell Curve Goddess.

Please also understand that, unless things have changed, there is no half-mark awarded in O-Level Maths. Also it is nigh impossible for ECF if the part involved only carries 1 mark.

Congratulations for surviving the first day of Halloween Week! Hang in there!

P.S. Just found another note on my Mistress’ desk. I think this could be especially helpful to those of you who may simply be exhausted after this “evil” week.

@Spyti: Really depends on the mark scheme but there could be a slight chance of leniency since Q5(b)(ii) carries 3 marks, provided you show all your substitutions of y & x clearly.

I made a mistake for question 7b as well since I did not include the length of DA and BC when considering the perimeter so I am also hoping that there will at least be an ecf of 1 mark. For question 6b, aren't we supposed to leave the answer in 3sf? That was what my friends and I all did. With regards to your worked solutions, the probability tree diagram 12/24 should be written as 1/2 isn't it since we are expected to write in the simplest form?

@Joe: Q7(b)(ii): As mentioned in the past, ecf will ultimately depend on the mark scheme but at least this part contains 2 marks so you can only hope.

Q6(b): This has been debated to the death in the past (notice Miss Loi was a lot more cheong hei back then :P). In a nutshell, 3sf only applies when the degree of accuracy is not specified and the answer is not exact (see instructions on cover page).

As the mass of the completed ramp ended up with an exact number (with 3 dp) computed from exact numbers in every step of the workings, strictly speaking, you are effectively decreasing the accuracy of the final answer if you approximated it to 3sf.

But then again, it all depends on how strict the mark scheme is this and Miss Loi has seen many got away with this.

Q10(b)(i): Fractions in simplest form are only explicitly required in Q10(b)(ii). It's just Miss Loi's style to leave it this way in general to facilitate quick checking of all branches in a probability tree diagram 🙂

@Jill: It's difficult to know as it depends on the marks scheme and how far 'off' your sketched graph is, but your best bet for some marks would be on the correct drawing of the line y=2 in 3(c) and the line in 3(e)(i) and, perhaps, your clear workings for the gradient in 3(d).

* 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

And what she mentions about her ability to spot exam questions, it’s true! … [read more]

## 8 Comments

曜

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is there ecf marks for question 5(b)? I did the gradient wrongly and got y=-7/4x+12.

B)part 2 i continued doing and got different answers. Plz help

曜

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@Spyti: Really depends on the mark scheme but there could be a slight chance of leniency since Q5(b)(ii) carries 3 marks,

providedyou show all your substitutions ofy&xclearly.曜

日

Is there ecf marks for qn 7bii if I got qn 7bi incorrectly ?

Would appreciate your reply . Thank you ! 🙂

曜

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@Kom: *points below*

曜

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I made a mistake for question 7b as well since I did not include the length of DA and BC when considering the perimeter so I am also hoping that there will at least be an ecf of 1 mark. For question 6b, aren't we supposed to leave the answer in 3sf? That was what my friends and I all did. With regards to your worked solutions, the probability tree diagram 12/24 should be written as 1/2 isn't it since we are expected to write in the simplest form?

曜

日

@Joe: Q7(b)(ii): As mentioned in the past, ecf will ultimately depend on the mark scheme but

at leastthis part contains 2 marks so you can only hope.Q6(b): This has been debated to the death in the past (notice Miss Loi was a lot more

cheong heiback then :P). In a nutshell, 3sf only applies when the degree of accuracy is not specified and theanswer is not exact(see instructions on cover page).As the mass of the completed ramp ended up with an exact number (with 3 dp) computed from exact numbers in every step of the workings,

strictly speaking, you are effectively decreasing the accuracy of the final answer if you approximated it to 3sf.But then again, it all depends on how strict the mark scheme is this and Miss Loi has seen many got away with this.

Q10(b)(i): Fractions in simplest form are only explicitly required in Q10(b)(ii). It's just Miss Loi's style to leave it this way in general to facilitate quick checking of all branches in a probability tree diagram 🙂

曜

日

hi I've sketched my graph wrongly do u think there will any ecf for question 3? thank u

曜

日

@Jill: It's difficult to know as it depends on the marks scheme and how far 'off' your sketched graph is, but your best bet for some marks would be on the

correctdrawing of the liney=2 in 3(c) and the line in 3(e)(i) and, perhaps, your clear workings for the gradient in 3(d).