Wednesday 30 May 2018

SMO 2018 (Junior Section) Answers

SMO 2018 Junior Rd 2 Namelist

Junior Round 2 Cut-off: 16

SMO 2018 Junior Rd 2 Questions

SMO 2018 Junior Questions

SMO 2018 (Junior Section) Answers

1. E
2. B
3. D
4. C
5. B
6. 100
7. 11
8. 180
9. 3003
10. 810
11. 54
12. 5200
13. 550
14. 904
15. 90
16. 35
17. 1440
18. 3200
19. 20800
20. 2
21. 9
22. 25249
23. 568
24. 90
25. 1009

90 comments:

Unknown said...

how do u get the ans for q25

Justin said...

how is q25 1009

matharena said...

Considering x terms,
1 - (1-x) + (1-x)^2 - (1-x)^3 + (1-x)^4 - ... - (1-x)^2017
= x - 2x + 3x - 4x + ... + 2015x - 2016x + 2017x + ...
Coefficient of x
= 1 - 2 + 3 - 4 + ... + 2015 - 2016 + 2017
= 1008(-1) + 2017
= 1009

Anonymous said...

Why is there 25 qns this year?

Anonymous said...

Any idea what may be the cut off score this year?

Anonymous said...

Why is 54 the answer for question 11?

Anonymous said...


somebody say, cut off : 12--13

Anonymous said...

Is 16 enough for gold?

Anonymous said...

This year's paper is much more easier, which includes many primary school questions. Personally I think. And the format changed

Anonymous said...

The format had changed

Anonymous said...

how many questions must we get correct for bronze/silver/gold

Anonymous said...

How much do you think we'll need to get gold?

Anonymous said...

I got 20 out of 25 for the first round but then my coach said i might not make the second round.

Anonymous said...

yes, much easier and longer time for each try. 21 as cut off point will not be surprise.

Anonymous said...

Some questions were doable, some were hard

Anonymous said...

thanks yall for making me look like an idiot :') i probably got like 6

Celiney said...

Is 10 enough for honourable mention?

Anonymous said...

Guys I need your help. Is 16 to 17 enuf for silver?

Anonymous said...

Will they be more lenient in this time’s grading system? Coz I think there are fewer choices of questions to choose from, which means that the paper is more difficult the scope is narrower.

Anonymous said...

Guys what rank is 15???

Anonymous said...

Hi guys, is 16 enough for Round 2/ Gold?

Anonymous said...

Everyone who goes to round 2 is guaranteed silver, and in order to get gold you must get into round 2 and do well in it I think.

Anonymous said...

Wait if we can get 15 can we get into the second round. My friend said the cut-off should be about 10-15, but I am not sure. How am I supposed to know?

Anonymous said...

Guys I got like 6 will that get me into round 2? I really want top 30

Anonymous said...

I think that is participation tbh

Anonymous said...

Is 20 enough for round 2??

Anonymous said...

Will 10 get me a silver? I want to get into 2nd round badly...

Anonymous said...

Is 12 enough for a bronze?

Anonymous said...

I would estimate the round 2 cut-off to be around 17-18 probably

Anonymous said...

@anon who got 6 yeah u round 2 and gold.

Ben said...

What'll be the cutoff point for this year? I got 21/25...not sure if that's enough...I know people who got 24...

Anonymous said...

How do u get ans for q12?

Anonymous said...

This years paper was very easy. I checked my answers and I think that I got 25/25

Anonymous said...

What is the total mark required to get top 30 ... special round seems very difficult

Anonymous said...

Will 15 get me a sliver?I really want to get top 30

Anonymous said...

I checked my answers and I think that I got 15/25. Is it enough for a bronze?

Anonymous said...

I got around 12 correct.. would that get me at least a bronze?

Anonymous said...

Is 20 enough for round 2? Primary 6 here.

Anonymous said...

Q12 is not 5200.Let the total number of phone is p.
We have: 1800=200*(p-2)-m/p
=>1800=200p-400-m/p
=>2200=200p-m/p
=>p>=2200/200=11
In other way, m is smallest so p is also smallest.
If p=11 => we have: 2200=2200-m/11
=>0=0-m/11
=>m=0
But m cannot be 0 so species
If p=12 => we have: 2200=2400-m/12
=>0=200-m/12
=>m/12=200
=>m=2400
Thus the smallest value of m is 2400

Anonymous said...

p is a prime

Anonymous said...

is ten enough for a award?

Unknown said...

what will 14 get me?

Anonymous said...

14 will get you bronze to silver. Likely bronze.

Unknown said...

Can anybody help me with qn 18 ? Its pretty confusing

Anonymous said...

News!! SMO ROUND 2 RESULT CAME OUT!! CHECK EMAIL AND WITH YOUR RESPECTIVE SCHOOLS!!! I got 20/25 and got in round 2!! Can someone say how much they get so we know the COP?

Anonymous said...

Hello, are the round 2 namelist out online already?

Anonymous said...

If so, can you send me the link to the name list?

Anonymous said...

Cutoff should be about 15. Anyone getting below 15 and got into round 2?

Anonymous said...

16/25 here.... chances of getting into R2? I understand I'm treading on a tightrope (between getting and not getting into R2) here....
Have yet to receive email although nobody I know has, even those with >18 questions correct... is there perhaps a namelist you can share?

Anonymous said...

i have got the list of 2nd round participant, it is given via email. i can try to find your name if you give your initial name. only 230 names on my list

Unknown said...
This comment has been removed by the author.
Anonymous said...

Is it ok to just send the list so everyone can check themselves?

Anonymous said...

hey justyn, what were you wrote before? haha, congrats btw! how many questions you got right?

Anonymous said...

Are there any Chung Cheng High Main winners?

Anonymous said...

Yes, only one. entry number 18 : Young Y H

Anonymous said...

@ Justyn, for question number 18, just make a line from D to C, after that you can solve it using area of triangle. -Hd

Anonymous said...

Will the list of round 2 participants be posted here?

Anonymous said...

https://goo.gl/zh9jf4

R2 list for your reference (I suppose there are no inaccuracies)

Cutoff this year should have been 16 - I'm the 16/25 boy (refer to comment on 11 June at 2203) and I know people with 15/25 who are not in R2

Anonymous said...

Any idea how many people participated? I wanna know what is the percentage cutoff for round 2 participants.

Anonymous said...

Top 10% in R2 so ~2300 ppl

Anonymous said...

Does the list provided only contain of Sec 1s?

Anonymous said...

Do u have senior and open lists

Anonymous said...

Results out at SMS website:

Junior http://sms.math.nus.edu.sg/Competitions/SMO2018/R2Junior-2018.pdf

Senior http://sms.math.nus.edu.sg/Competitions/SMO2018/R2Senior-2018.pdf

Open http://sms.math.nus.edu.sg/Competitions/SMO2018/R2Open-2018.pdf

Good lucks to all...

Anonymous said...

Yes I think the list only contains of Sec 1s

Anonymous said...

is 10-11 enough for bronze?

Anonymous said...

I got 25/25; I got into Second Round.

Anonymous said...

I got selected for Round 2

Anonymous said...

Congrats!

Anonymous said...

question 1 of round 2 is recycled from past year.

Anonymous said...

What is the answer for Question 2 of SMO round 2?

Anonymous said...

I think Q2 of SMO round 2 is 14√2
By hypothesis, it's easy to prove that ABC is an equilateral triangle

Anonymous said...

No its 14

Anonymous said...

You have to use similarity laws making triangle ABC similar to triangle BCD to find BD as square root of 196 so BD = 14

Anonymous said...

Can someone share the Round 2 answers. I felt it was a bit too hard.

Piauw said...

Was it too hard? It was actually easier than last year IMO
I believe the answers are somewhere along these lines
1. (8,1), (4,4), (0,7)
2. 14
3. 1023 (on hindsight I believe it is 2047 or 2048)
4. 130
5. 5-12, 14

Can someone check? Thanks in advance

Anonymous said...

I think I got like 39

Anonymous said...

Is it good?

Anonymous said...

wow, 39? is that your score on 2nd round only? and will the result from previous round get added to my score on the round 2? i think i got 30 for 2nd round and 20 from the first round. how much more point usually needed on the 2nd round to get gold? i think that 2nd round question from previous year is almost impossible to answer by normal student,only this year that's really easy

Anonymous said...

Yes 39 out of 50 on round 2

Anonymous said...

Hi guys, what do you think is the mark for top 30, like 50/ 75???

Anonymous said...

Hi guys, when are the round 2 results going to be out? I want to know how I did>

Anonymous said...

@piauw
1:yes
2:yes
3:how did you get 1023!?!?! I got 23... like firstly, both sides cannot be even
Obviously first case is 1
Then next using my poor logic, I found that for the greatest common divisor=1, one side must be prime numbers >50 (eg 1x47) other side is 100!/47, the greatest common divisor will be 47 even though it is prime because 47x2=94 is there and 94 can divide by 47...
So cases is 11 primes >50 times 2(53 and 53x1) + original 1 case
4:they asked for the integers... not how many...
5: you said pentagon can be made but interior angle of pentagon is 108.. how do you make 108 with 60 and 90 only?

Anyway I am just stupid boy correct me because I sure as hell 99% am wrong

Anonymous said...

Any 1 here revising for SMO 2019

Anonymous said...

me

SMO 2019 said...

Hello Lim Jeck, I appreciate your blogs, when will the 2019 answers come out?

Ryan Au Eong said...

Could you send the answers to the SMO senior section 2019?

Anonymous said...

out alr

Anonymous said...

out alr

Anonymous said...

Is the junior section out

Anonymous said...

Is 30/25 enough for round 3? Primary 1 here.