Berikut ini adalah soal beserta kunci jawaban Fermat Mathematic Olympiad (FMO) 2021 grade 3 (Sc: Edukultur Indonesia)

1. What should be filled in the question mark?

A.

B.

C.

D.

E.

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

A. 6

B. 9

C. 13

D. 14

E. 15

3. Given the timetable of a circular bus travelling around the city. Lucy wants to

travel from Museum to the Cathedral. If she is waiting for the bus beside the

Museum at 12:15, how many minutes does she have to spend on the bus?

A. 48

B. 34

C. 52

D. 55

E. 50

4. Candace stacked identical boxes to build the shape below. At least how many

boxes did she use?

A. 23

B. 20

C. 21

D. 22

E. 19

5. There were two types of egg boxes. Each box contains either 8 eggs or 12 eggs. Anna bought some boxes. Which answer below CANNOT be the total number of eggs bought by Anna?

A. 16

B. 20

C. 28

D. 26

E. 24

6. The scores of 5 students are recorded in the chart with equally-spaced lines

below. The greatest score difference between two friends are 16. Find the total

sum of scores of 5 students.

A. 80

B. 90

C. 64

D. 48

E. 100

7. The shape including 14 cubes below is painted all over the surface (even the

bottom). How many cubes having 4 faces painted are there?

A. 6

B. 7

C. 8

D. 9

E. 10

8. Find the missing number in the table below.

A. 43

B. 32

C. 24

D. 22

E. 34

9. Grandma has some candy jars. Each jar contains 2 apple candies and 4 banana

candies OR 3 apple candies and 3 banana candies. Given that she has 17 banana

candies. How many apple candies does she have?

A. 14

B. 13

C. 15

D. 12

E. 11

10. Teacher has a square piece of paper. She folds it in half three times then cuts

out two triangles as the figure below. What does the paper look like after being

cut?

A.

B.

C.

D.

E.

11. A box contains 2 pencils, 3 red ball pens, 4 blue ball pens and 5 black ball pens. Amy cannot look into the box but she wants to take out 3 ball pens of the same color. What is the least number of pens she needs to take out to make sure?

A. 7

B. 3

C. 9

D. 12

E. None of the above

12. Which figure needs the least paint to be completely filled with color?

A.

B.

C.

D.

E.

13. Candace uses 3 squares and 1 rectangle to form a bigger square as below. If the perimeter of the smallest square is 12cm, what is the perimeter of the shade

rectangle in cm?

A. 18

B. 24

C. 36

D. 40

E. None of the above

14. Find the suitable number to replace the question mark.

A. 24

B. 26

C. 12

D. 18

E. None of the above

15. Based on the pattern below, find the sum of all numbers in \(20^{th}\) row.

A. 314

B. 74

C. 326

D. 341

E. None of the above

16. 1 people living on an island. Some of these people are truth-tellers and the others are liars. The truth-tellers always tell the truth whereas the liars always lie. Each day, one of the people says “When I have left the island the number of truth-tellers will be the same as the number of liars.” Then this person leaves the island. After 2021 days there is no longer anybody living in the island. How many truth-tellers were living there in the beginning?

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