Berikut ini adalah soal beserta kunci jawaban Fermat Mathematic Olympiad (FMO) 2021 grade 4 (Sc: Halaman facebook FMO)

1. What should be filled into the cell with question mark?

A.

B.

C.

D.

E.

2. Idiana Jones discovers a tomb with mysterious symbols on the door. Given that \(\triangle\) and \(\bigcirc\) are both 2-digit numbers, find the smallest value of the sum \(\triangle + \bigcirc \).

A. 10

B. 20

C. 30

D. 40

E. 50

3. A round table is seen from many directions. Which figure is different?

A.

B.

C.

D.

E.

4. .A pizza is divided into 8 equal slices. Amy eats up \(\frac{1}{4}\) of the pizza. Then Betty eats up \(\frac{1}{2}\) of the remaining pizza. How many slices are left finally?

A. 1

B. 2

C. 3

D. 4

E. 5

5. In an online math lesson, teacher gives an example about a 4-digit number divisible by 9. However, Minh only heard three first digits, which are 1, 7 and 8 respectively. Let’s help him find out the last digit of the number.

A. 9

B. 2

C. 3

D. 0

E. 5

6. How many squares are there in the figure below?

A. 10

B. 14

C. 19

D. 17

E. 18

7. They can use 4 planks to make one pen for a goat and 7 planks to make two pens for two goats. If they want to make four pens for four goats, at least how many planks do they need to use?

A. 12

B. 14

C. 10

D. 16

E. 11

8. A carpenter cuts a long piece of wood into 2 smaller parts in 20 seconds. If he wants to cut a piece of wood into 6 smaller parts, how long does it take him?

A. 50 sec

B. 60 sec

C. 80 sec

D. 120 sec

E. 100 sec

9. The figure below plots the body temperature records of one patient in a day. The records started at 00:00 AM and were taken every 4 hours. When the temperature reached the highest, how many times had the patient been checked?

A. 2

B. 4

C. 5

D. 16

E. 20

10. They put 5 numbered crickets in the same maze. Their path is marked red as below. Which cricket travels the longest distance?

A. 1

B. 2

C. 3

D. 4

E. 5

11. Given 4 types of rice sack A, B, C, and D with weight of 10kg, 20kg, 30kg and 40kg not in that order. The seller doesn’t know the weight of type C so he put them on the scale as follows. How many kilograms does a rice sack C weigh?

A. 20kg

B. 10kg

C. 40kg

D. 30kg

E. None of the above

12. Refer to the pattern below. How many cells are shaded in the \(15^{th}\) figure?

A. 60

B. 61

C. 62

D. 63

E. None of the above

13. The librarian makes a bar graph to show how many books are borrowed in a week. However, the information about the Sunday is missing. Given the average number of borrowed books in the week is 130 books per day. Let’s help the librarian to find the number of borrowed books in Sunday.

A. 160

B. 40

C. 150

D. 20

E. None of the above

14. There are 13 red marbles, 15 blue marbles, 18 green marbles, 14 white marbles in a secret box. Lucy picks out marbles without looking. At least how many marbles should she pick out to make sure that she gets 4 red marbles and 7 blue marbles?

A. 11

B. 43

C. 51

D. 52

E. None of the above

15. The worker uses 12 cubic blocks to build a 2-step flight of stair as the figure below. To prevent it from getting damaged, he covers all the surfaces of the stair with hard tiles, except for the bottom. It takes him 2 minutes to lay one tile. How many minutes does it take him to do the whole task?

A. 38

B. 44

C. 76

D. 48

E. None of the above

16. Anna stacks four identical dice as follows. Given that on each die, the total number of dots on each pair of opposite faces is 7. Elsa looks at the stacks from behind. Each letter \(F, M, O, D, I, C, E\) represents the number of dots on the face of the dice. Find the value of \(F +M\times O- D + I \times C – E\) .

(Different letters can represent a same number)

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