Tuesday 3 June 2014

SMO 2014 (Junior Section) Answers

SMO 2014 Junior Round 1 Questions
SMO 2014 Junior Round 2 Questions

SMO 2014 (Junior Section) Answers

1. C
2. D
3. E
4. A
5. D
6. E
7. A
8. C
9. D
10. E
11. 28
12. 21
13. 60
14. 935
15. 16
16. 2017
17. 8
18. 491
19. 52
20. 4008
21. 10
22. 24
23. 2
24. 25
25. 22
26. 0 (question is wrong as x is not real!)
27. 2
28. 2500
29. 2809
30. 203
31. 5956
32. 1
33. 44
34. 144
35. 4

Initial answers are provided by a Year 1 NUS High student who does not wish to be named.

SMO (Junior) Previous Years' Cut-off Points (Inclusive of Round 2 scores)
2013 Gold (27), Silver (11), Bronze (8), HM (7), Round 2 (13), Top 30 (~50)
2012 Gold (17), Silver (8), Bronze (6), HM (5), Round 2 (8)
2011 Gold (12), Silver (9), Bronze (7), HM (6), Round 2 (11), Top 30 (~34)
2010 Gold (24), Silver (9), Bronze (8), HM (5)
2009 Gold (11), Silver (7), Bronze (6), HM (5)
2008 Gold (23), Silver (14), Bronze (11), HM (10)
2007 Gold (20), Silver (14), Bronze (11), HM (10)

36 comments:

Anonymous said...


thank you very much. You are so helpful

from leopard

Anonymous said...


the answer for question 26 is deffinitelly 0, no need double-check.

花豹

Anonymous said...

For Q26, try to find a real value for x.
The qn is wrong.

Anonymous said...

Seems to me that this year's paper is easier.

Anonymous said...

Qn 13, 14 , 17 workings to share??

Anonymous said...

There were some killer questions in this year's Junior paper

SKATER said...

For qn 13, let (x-7)/(x-8) be 1-1/(x-8) and do the same for the rest. You will be left with 1/(x-9) - 1/(x-8) = 1/(x-12) - 1/(x-11) then just solve the equation to get x=10.

SKATER said...

For qn 17, you will see that the two smallest positive divisors are 1 and 5 (to get 5, we have 6-1 since 1 is definitely the smallest divisor of N). Similarly we are sure that the largest divisor is N itself. The second largest divisor is simply N/5. Therefore, 1122=N+1/5N. Thus, n =935

Anonymous said...

Thx for replying melo

Anonymous said...

Hi Melo, I think your ans for Qn 17 is meant for Qn14? So may I know the workings for Qn 17 Thanks.

Unknown said...

Hi, what do you predict the round 2 cut off point for this year to be?

Anonymous said...

Hi, I also want to know the cut-off points for all levels, can Jeck you tell us pls? when can we know?

SKATER said...

Hey guys, the results for second round will be out soon, perhaps in another 2 weeks time. Be patient. :)

Anonymous said...

But the 2nd round is on the 28th so usually they should let the school know by this week rite so that the students can prepare ?

SKATER said...

Not necessarily. They sometimes (or usually) release results one week before the second round.

Anonymous said...

@melo, sometimes they release on 15th , haish...wonder what is the cut off point this time lol for all levels?

SKATER said...

I am guessing for senior will be around, if not more than 15, and for open will be around 14 (or more) :)

Anonymous said...

junior?

SKATER said...

Not too sure... Havent taken the paper so not too sure abt the average score... Maybe more than 15 definitely?

Unknown said...

Which junior paper did you guys think was harder? 2013 or 2014?

Anonymous said...

It can only be easy to some students who have high calibre or special training. It has never been easy for all years.

Unknown said...

As in in comparison.

SKATER said...

I'm not too sure about Junior but I know that Senior is much easier than last year. Last year's paper was a killer. I have looked through this year's Junior and it seems quite easy, but I haven't seen last year's so can't really make a comparison.

Anonymous said...

It was hard lol for junior...I think I couldnt make it to 2nd round...so sad.

SKATER said...

don't be sad lol.... u still have many years to try SMO :p

Anonymous said...

I got 12 or 13 ( I'm not so sure because I guessed 2 MCQ) but didn't make it . I've got a friend who got 14 but made it into the second round . so I'm guessing cut off point is either 13 or 14 . note that I'm referring to the SMO Junior by this. And for open , I think it's between 9 and 11(according to my senior )

SKATER said...

No. Open is 14 marks.

Anonymous said...

What is the cut off point for junior?

Anonymous said...

The cut-off point for SMO Junior should be 14 then since I got 13 and did not make it into the 2nd round and Anonymous mentioned that he had a friend who made it into the 2nd round with 14.

Anonymous said...

How to know how much the student got? Where to get this information? Thanks in advance!

Anonymous said...

round 2 qn 5,

In an 8x8 grid,n disks, numbered 1 to n are stacked, with random order, in a pile in the bottom left corner. The disks can be moved one at a time to a neighbouring cell either to the right or top. The aim to move all the disks to the cell at the top right corner and stack them in the order 1,2...,n from the bottom. Each cell, except the bottom left and top right cell, can hv at most one disk at any given time. Find the largest value of n so that the aim can be achieved.

can someone help to answer? Thanks.

Unknown said...

I solved the question like this: Move the disks into the following formation. In this formation, no matter where disk 1 or 2 or any other disk is, there is always a pathway to the top right square. Take 'x' to be a disk, 0 to be an empty square.
xooooooo
xoxoxoxo
xoxoxoxo
xoxoxoxo
xoxoxoxo
xoxoxoxo
xoxoxoxo
xoxoxoxo
So the total number of disks is 8+7+7+7=29

Anonymous said...

How to do q4 of round 2

S R Sai said...

Can u help crack 7th Qn in SMO Junior Round 1 2014

S R Sai said...

The 7th problem is
TERRIBLE
+ NUMBER
-----------------
THIRTEEN
------------------

tran quoc binh said...

For question 7, we have:
L = 9
U = 0 ( => I >=1)
E + 1 = H

Suppose R <= 7
R + N = 10 + I, because I > 0 therefore N >= 4
E + R = N, therefore E >=7
B + B + 1 = 10 + E --> B >=8, --> B = 8 (because L already = 9)
Because B = 8 --> E = 7 (8 + 8 + 1 = 17)
Because H = E + 1 --> H = 7 + 1 = 8 what is impossible because B already = 8.

Therefore R = 8
R + N = 10 + I --> N >= 3
E + R = 10 + N --> E >= 5
B + B + 1 = 10 + E --> B >=7, because R = 8, L = 9 then B = 7 and E = 5
E + 1 = H --> H = 6
E + R = 10 + N --> N =3
N + N = 10 + I --> I = 1
At this moment we have only two values (2 and 4) for M and T , and M = 2, T = 4