ASEAN PRIMARY SCHOOLS MATHEMATICS OLYMPIAS 2003 SOLUTIONS

Solution 1 :
41 - 5 = 36
12 : 9 : 1 = 36 : 18 : 3
2003 - 3 = 2000

Solution 2 :
(100 - 3x) - (40 - 2.4x) = 6
60 - 5.4x = 6
5.4x = 54
x = 10

Solution 3 :

Solution 4 :
x + y + z = 6
Take more than 5 less than 9 = 6

5x + 10y + 50z = 75
x min = 1, z max = 1

Assume z = 0
x = 1, y = 6 - 1 = 5
5 + 10(5) < 75


Assume z = 1
x + y = 5, x = 5 - y
5(5 - y) + 10y + 50 = 75
25 - 5y + 10y = 25
5y = 0, y = 0, x = 5

There are no $10 coin.

Solution 5 :
S + 2M + L = 10.
S + 2M + 2L = 15
L = 5
S + 2M = 10 - 5 = 5
2S + 4M = 2 x 5 = 10

Solution 6 :
A579B divisible 12 where A odd and B even number
A = 1 B = 2,
A = 7 B = 2,
A = 3 B = 6,
A = 9 B = 6.

Solution 7 :
ABC x E = 2032
If E = 9, 2032 is not divisible by 9
If E = 8, 2032 / 8 = 254, A = 2, B = 5, C = 4
ABC x D = 762
254 x D = 762
D = 3
Prof :
254 x 38 = 9652

Solution 8 :
1/2 x 8 x (5 + 7 + 6) - 1/2 x 8 x 6 + 1/2 x 8 x (7 + 6) - 1/2 x 8 x 6 =
1/2 x 8 x (5 + 7) + 1/2 x 8 x 7 =
48 + 28 = 76 cm2

Solution 9 :
I : 22/7(1/2x)^2 / x^2 = 22/7 x 1/4 = 22/28 = 11/14
II : 22/7(1/4x)^2 / x^2 = 22/7 x 1/16 x 4 = 22/28 = 11/14
III : 22/7(1/16x)^2 / x^2 = 22/7 x 1/64 x 16 = 22/28 = 11/14

Solution 10 :
11/14 x 100% =  78.57%

Solution 11 :
Keliling lingkaran = πD
DA : DB = 12 : 36 = 1 : 3
rpmA : rpmB = 3 : 1 = 450 : 150
rpmB = rpmC
DC : DD = 9 : 27 = 1 : 3
rpmC : rpmD = 3 : 1 = 150 : 50
rpmD = 50

Solution 12 :
(3 x 2 x r) + (3 x 1/3 x 22/7 x 2 x r) =
(3 x 2 x 7) + (3 x 1/3 x 22/7 x 2 x 7) =
42 + 44 = 86 cm

Solution 13 :
0.12x = 5 -2
0.12x = 3
x = 25

Solution 15 :
2A < B
A + C < B
B < D
C = 6
D = 9
A + 6 < B < 9
If A = 1 then 7 < B < 9, B = 8