The Southeast Asia Mathematical Olympiad (SEAMO) is an international Math Olympiad competition that originated in Singapore and was founded by Mr. Terry Chew in 2016 in 8 Southeast Asian Countries. Since then, it is growing its popularity around the world. In 2019 it was recognized by 18 countries. In 2020 total number of participating countries increased to 22, including students from Indonesia, Brazil, China, Newzealand, and Taiwan students enrolled in SEAMO 2022-23.

**Problem and Solution SEAMO 2016 paper A**. Soal ini bersumber dari seamo-official.org

1. What is the missing number?

(A) 17

(B) 19

(C) 21

(D) 23

(E) 30

2. How many triangles are there in the figure below?

(A) 10

(B) 11

(C) 12

(D) 13

(E) 14

3. Vanessa uses some coins to form a triangle. Each of the 3 corners of the triangle has a coin. There are 6 coins on each side of the triangle. How many coins does Vanessa use to form the triangle?

(A) 12

(B) 13

(C) 14

(D) 15

(E) 16

4. What is the result of

\(50×101?\)

(A) 1010

(B) 4350

(C) 5050

(D) 10100

(E) 5050

5. The sum of two numbers is 80. The difference between the two numbers

is 12. What is the value of the bigger number?

(A) 32

(B) 40

(C) 46

(D) 48

(E) 52

6. Find the sum of

\(1 + 2 + 3 + 4 + ⋯ + 18 + 19 + 20\)

(A) 190

(B) 195

(C) 200

(D) 210

(E) 220

7. How many tiles do you need to cover the area shown below?

(A) 2

(B) 3

(C) 4

(D) 5

(E) 6

8. In which row is the number 47 if the numbers continue?

(A) Row A

(B) Row B

(C) Row C

(D) Row D

(E) Row E

9. Find the sum of

\(2 + 22 + 222 + 2222 + 22222\)

(A) 24 680

(B) 24 690

(C) 24 700

(D) 24 710

(E) None of the above

10. What is the least number of colours needed to colour the petals such that no two neighboring petals have the same colour?

(A) 2

(B) 3

(C) 4

(D) 5

(E) 6

**Problems And Solutions SEAMO PAPER A 2017**

**Problems and Solutions SEAMO PAPER A 2020**