Đề HKIMO vòng chung kết quốc gia 2020 Khối 4 (Có đáp án)

Đề HKIMO Vòng Chung kết Quốc gia 2020 – Khối 4 
 Logical Thinking 
1. Andy has 68 marks and John has 72 marks in Mathematics exam. If the 
 average mark of Andy, John and Mary is 51, what is Mary’s exam marks? 
 Marks: Điểm; Average mark: Điểm trung bình. 
2. If 13th June, 2020 is Saturday, which day of the week will 23rd March, 2020 be? 
 Day of the week: Thứ trong tuần. 
3. A tree grows 1 meter every year. But it will cut into half every 15 years. If a 
 tree is now 7 meters tall after cutting, how many meter(s) will the tree be 55 
 years later? 
 Half: Một nửa; Meter: Mét. 
4. According to the pattern shown below, what is the number in the blank? 
 Pattern: Dãy có quy luật. 
 Question 4 
5. There are a total of 48 chickens and rabbits in a farm. The animals have a 
 total of 112 legs. How many chicken(s) is / are there? 
 Total: Tổng số. 
 Arithmetic 
6. Find the value of 13 18 + 24 11 + 11 2 + 13 10 . 
 Value: giá trị. 
7. Find the value of 66 17 + 123  51 − 10  34 . 
 Value: giá trị. 
KỲ THI OLYMPIC TOÁN HỌC QUỐC TẾ HKIMO 2021 – 2022 
Đơn vị đồng tổ chức tại Việt Nam: Trường Đại học Thủ Đô Hà Nội và FERMAT Education. 
 Geometry 
16. How many rectangle(s) with “*” is / are there in the figure below? 
 Rectangle: Hình chữ nhật. 
 * 
 Question 16 
17. How many rectangle(s) is / are there in the figure below? 
 Rectangle: Hình chữ nhật. 
 Question 17 
18. The perimeter of a rectangle is 68cm. If sides of the rectangle are integers, 
 find the minimum value of the area of the rectangle. 
 Perimeter: Chu vi; Rectangle: Hình chữ nhật; Side: Cạnh; Integer: Số nguyên; Minimum 
 value: Giá trị nhỏ nhất; Area: diện tích. 
19. At least how many square(s) can be seen if viewing the figure below from 
 the right? 
 At least: Ít nhất; Square: Hình vuông; The right: Phía bên phải. 
 Question 19 
KỲ THI OLYMPIC TOÁN HỌC QUỐC TẾ HKIMO 2021 – 2022 
Đơn vị đồng tổ chức tại Việt Nam: Trường Đại học Thủ Đô Hà Nội và FERMAT Education. 
Đề ôn tập HKIMO số 1 – Khối 4 
 Logical Thinking 
1. Amy gets 58 marks in Chinese exam and she gets 85 in English exam. If she 
 has an average of 74 marks on Chinese, English and Mathematics exam, how 
 many marks does she get in Mathematics exam? 
 Average: Điểm trung bình; Mark: Điểm. 
2. The sum of father’s and mother’s ages is 93. If the age of father 3 years ago 
 was the same as the age of mother 8 years later, how old is father now? 
 Sum: Tổng; Age: Tuổi; Ago: Trước đây; Later: Sau đó, The same as: Bằng nhau. 
3. A stationery store had a batch of pencils. One half but 8 fewer pencils were 
 sold on the first day. One half of the remaining part but 9 fewer pencils were 
 sold on the second day. Finally 33 pencils are left. How many pencil(s) did 
 the stationery store have originally? 
 One half: một nửa; the remaining part: Phần còn lại; Fewer: Ít hơn; Left: Phần 
 còn lại. 
4. 28th March is Thursday. Which day of the week is 23rd August in the same 
 year? 
 Day of the week: Thứ trong tuần; The same: Bằng nhau. 
5. There are a total of 28 chickens and rabbits in a farm. The animals have a 
 total of 72 legs. How many chicken are there? 
 Total: Tổng cộng 
 Arithmetic 
6. Find the value of 6+ 7 + 8 + ... + 43 + 44 . 
 Value: giá trị 
7. Find the value of 1111 1111. 
 Value: giá trị 
8. Find the value of 24 17 + 17 28 2 . 
 Value: giá trị 
9. Find the value of 132 6 + 234  6 + 384  6. 
 Value: giá trị 
KỲ THI OLYMPIC TOÁN HỌC QUỐC TẾ HKIMO 2021 – 2022 
Đơn vị đồng tổ chức tại Việt Nam: Trường Đại học Thủ Đô Hà Nội và FERMAT Education. 
18. The rectangle below is cut into 7 squares. If the perimeter of the rectangle is 
 160cm, find the area of the larger square. 
 Rectangle: Hình chữ nhật; Square: Hình vuông; Perimeter: Chu vi; Area: Diện 
 tích; Larger: Lớn hơn. 
 Question 18 
19. The perimeter of an equilateral triangle is 90cm. Now Andy cut the triangle 
 to 4 smaller identical equilateral triangles. What is the sum of perimeter of 
 the small triangles in cm? 
 Perimeter: Chu vi; Equilateral triangle: Tam giác đều; Triangle: Tam giác; 
 Identical: Bằng nhau; Sum: Tổng. 
20. How many right-angled triangle(s) is / are there in the figure below? 
 Right-angled triangle: Tam giác vuông 
 Question 20 
 Combinatorics 
21. Amy draws all triangles whose perimeter is 16cm and length of sides are 
 integers. How many different types of triangle(s) does she draw? (triangles 
 with sides (3,5,6) and (5,3,6) are regarded as the same type of triangle) 
 Perimeter: Chu vi; Triangle: Tam giác; Length: Độ dài; Side: Cạnh; Integer: Số 
 nguyên; The same: Giống nhau. 
22. Use digits 2, 3, 5 and 6 to form a 4 digit number such that the tens digit and 
 thousands digit are even while the units digit and hundreds digit are odd. 
 How many such 4 digit number(s) is/are there? 
KỲ THI OLYMPIC TOÁN HỌC QUỐC TẾ HKIMO 2021 – 2022 
Đơn vị đồng tổ chức tại Việt Nam: Trường Đại học Thủ Đô Hà Nội và FERMAT Education. 
Đề ôn tập HKIMO số 2 – Khối 4 
 Logical Thinking 
1. Alice has 51 marks and Peter has 65 marks in Mathematics exam. If the 
 average mark of Alice, Peter and Mary is 58, what is Mary’s exam marks? 
 Marks: Điểm; Average mark: Điểm trung bình. 
2. The sum of Alice’s and Peter’s ages is 47. If the age of Alice 2 years ago was 
 the half of the age of Peter 6 years later, how old is Alice now? 
 Sum: tổng; The half of: Một nửa/ 
3. A book store had a box of books. One half but 6 more books were sold on 
 the first day. Two third of the remaining part and 2 less books were sold on 
 the second day. Finally, 8 books are left. How many book(s) did the book 
 store have originally? 
 One half: một nửa; More: Nhiều hơn; Two third of the remaining part; hai phần ba 
 chỗ còn lại; Less: Ít hơn. 
4. 15th May is Friday. Which day of the week is 1st April in the same year? 
 Day of the week: Thứ trong tuần. 
5. There are a total of 36 chickens and rabbits in a farm. The animals have a 
 total of 80 legs. How many chicken(s) is / are there? 
 Total: Tổng số. 
 Arithmetic 
6. Find the value of 33+ 34 + 35 + 36 + ... + 66 + 67 . 
 Value: giá trị. 
7. Find the value of 111 11 101. 
 Value: giá trị. 
8. Find the value of 17 62 + 19 34. 
 Value: giá trị. 
9. Find the value of 1000 2 + 1000  10 + 1000  100. 
 Value: giá trị. 
10. Find the value of 2+ 4 + 6 + 8 + 10 + ... + 28 + 30. 
 Value: giá trị. 
KỲ THI OLYMPIC TOÁN HỌC QUỐC TẾ HKIMO 2021 – 2022 
Đơn vị đồng tổ chức tại Việt Nam: Trường Đại học Thủ Đô Hà Nội và FERMAT Education. 
18. The square below is cut into 5 squares and 1 rectangle. If the perimeter of the 
 original square is 120cm, find the area of the rectangle. 
 Square: Hình vuông; Rectangle: Hình chữ nhật; Perimeter: Chu vi; Area: diện 
 tích. 
 Question 18 
19. The perimeter of a square is 40cm. Now Alice combine 36 square to a big 
 square. What is the perimeter of the big square in cm? 
 Perimeter: Chu vi; Square: Hình vuông. 
20. How many right-angled triangle(s) is / are there in the figure below? 
 Right-angled triangle: Tam giác vuông (Tam giác có 1 góc bằng 900) 
 Question 20 
 Combinatorics 
21. A flight of stairs has 8 steps. Mary can go up for 1 step or 2 steps each time. 
 The 5th step cannot be stepped on as it is destroyed. How many way(s) is / 
 are there for Mary to go up the stairs? 
 Step: Bước; Go up: Bước lên trên; Way: Cách. 
22. 99 students are either wearing XL, L, M, S or XS size uniforms. At least how 
 many student(s) is / are wearing the same size of uniforms? 
 At least: Ít nhất, The same: Giống nhau. 
23. Alice has 40 $1 and $2 coins altogether. He has $58 in total. How many $1 
 coin(s) does she have? 
 Altogether: Tất cả; In total: Tổng số. 
KỲ THI OLYMPIC TOÁN HỌC QUỐC TẾ HKIMO 2021 – 2022 
Đơn vị đồng tổ chức tại Việt Nam: Trường Đại học Thủ Đô Hà Nội và FERMAT Education.