2021 澳洲 AMC C-Junior 真题 答案 详解
2021-10-06 auamc auamc C-Junior
| 序号 | 文件列表 | 说明 | ||
|---|---|---|---|---|
| 1 | 2021-C-Junior-paper-eng-zh.pdf | 9 页 | 401.04KB | 中英双语真题 |
| 2 | 2021-C-Junior-paper-eng.pdf | 6 页 | 170.27KB | 英文真题 |
| 3 | 2021-C-Junior-key.pdf | 1 页 | 22.12KB | 真题答案 |
| 4 | 2021-C-Junior-solution-eng.pdf | 9 页 | 1.99MB | 真题文字详解(英文) |
中英双语真题
2021 AUSTRALIAN MATHEMATICS COMPETITION JUNIOR Junior Division 1-10 Questions 1 to 10, 3 marks each 1. 2021 - 1202 = (A) 719 (B) 723 (C) 819 (D) 823 (E) 3223 2. What is the perimeter of this figure? (A) 28 units (B) 26 units (C) 24 units (D) 20 units (E) 21 units 3. The area of this triangle is (A) 10 cm² (B) 12 cm² (C) 12.5 cm² (D) 15 cm² (E) 16 cm² 4. On the number line shown, the fraction lies between (A) P and Q (B) Q and R (C) R and S (D) S and T (E) T and U
英文真题
2021 AUSTRALIAN MATHEMATICS COMPETITION JUNIOR Junior Division Questions 1 to 10, 3 marks each 1. 2021 - 1202 = (A) 719 (B) 723 (C) 819 (D) 823 (E) 3223 2. What is the perimeter of this figure? (A) 28 units (B) 26 units (C) 24 units (D) 20 units (E) 21 units 3. The area of this triangle is (A) 10 cm² (B) 12 cm² (C) 12.5 cm² (D) 15 cm² (E) 16 cm² 4. On the number line below, the fraction lies between 3/8 P Q R S T U 0 1/2 1 (A) P and Q (B) Q and R (C) R and S (D) S and T (E) T and U 5. Which of the following is closest to 2021? (A) 202 × 100 (B) 22 × 1000 (C) 20.2 × 100 (D) 10 × 20.2 (E) 100 × 2.2
真题文字详解(英文)
46 2021 AMC Junior Solutions Junior Solutions 1. 2021 - 1202 = 819, hence (C). 2. The horizontal segments are 6 + 2 + 1 + 1 + 4 = 14. The vertical segments are 2 + 1 + 2 + 2 + 5 = 12. Therefore the total perimeter is 14 + 12 = 26, hence (B). 3. With b = 6 and h = 4, the area is A = \frac{1}{2} × b × h = \frac{1}{2} × 6 × 4 = 12 cm^2, hence (B). 4. There are 4 intervals between 0 and 1, so these are quarters. Each quarter can be each cut in half to make eighths, and then \frac{3}{8} is between \frac{1}{4} = Q and \frac{1}{2} = R, hence (B). 5. The numbers are (A) 20 200, (B) 22 000, (C) 2020, (D) 202 and (E) 220. Of these, the closest to 2021 is 2020, hence (C). 6. Let X and Y be the points of intersection, as shown. Due to supplementary angles, ∠DXB = 180° - 43° = 137°. Due to corresponding angles, ∠DEF = ∠DXB = 137°. Due to corresponding angles x° = ∠BYF = ∠DEF = 137°. hence (E). 7. The correct calculation is 5 × 2 + 4 = 10 + 4 = 14, but Mr Meow's calculation is 5 + 2 × 4 = 5 + 8 = 13, which is one less, hence (B). 8. From 11:49 am, there are 11 minutes until midday. Since 75 - 11 = 64, the cake should come out of the oven at 1:04 pm, hence (A). 9. The number of people who now know the joke is 1 + 3 + 3 × 3 = 13, hence (C). www.amt.edu.au
