2022 澳洲 AMC B-UpperPrimary 真题 答案 详解

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中英双语真题

Upper Primary Questions
1-10 questions, 3 points each

1. 请问哪一个数是二十五万一千一百五十？
   (A) 150 (B) 205 (C) 20150 (D) 25150 (E) 205150

2. 请问右图中阴影部分占总面积的几分之几？
   (A) ( \frac{1}{2} ) (B) ( \frac{2}{3} ) (C) ( \frac{3}{4} ) (D) ( \frac{4}{9} ) (E) ( \frac{5}{9} )

3. 算式 2220 - 2022 =
   (A) 18 (B) 188 (C) 198 (D) 200 (E) 202

4. 小欧将以下三个数从小到大的顺序写下来：
   1.03 0.08 0.4
   请问他写下数字的顺序是什么？
   (A) 0.08, 1.03, 0.4 (B) 0.08, 0.4, 1.03 (C) 0.4, 0.08, 1.03 (D) 0.4, 1.03, .008 (E) 1.03, 0.4, 0.08

5. 当我的弟弟刚满3岁时我是7岁，请问当他刚刚满7岁时我是几岁？
   (A) 9 (B) 10 (C) 11 (D) 12 (E) 13

6. 右侧图案是由29个1cm x 1cm的正方形组成的。请问它的周长是多少cm？
   (A) 52 (B) 58 (C) 60 (D) 68 (E) 72

英文真题

8 2022 AMC Upper Primary Questions Upper Primary Questions 1. What number is two hundred and five thousand, one hundred and fifty? (A) 150 (B) 205 (C) 20150 (D) 25150 (E) 205150 2. What fraction of this picture is shaded? (A) 1/2 (B) 2/3 (C) 3/4 (D) 4/9 (E) 5/9 3. 2220 - 2022 = (A) 18 (B) 188 (C) 198 (D) 200 (E) 202 4. Audrey wrote these three numbers in order from smallest to largest: 1.03 0.08 0.4 In which order did she write them? (A) 0.08, 1.03, 0.4 (B) 0.08, 0.4, 1.03 (C) 0.4, 0.08, 1.03 (D) 0.4, 1.03, .008 (E) 1.03, 0.4, 0.08 5. I was 7 years old when my brother turned 3. How old will I be when he turns 7? (A) 9 (B) 10 (C) 11 (D) 12 (E) 13 6. This shape is built from 29 squares, each 1 cm x 1 cm. What is its perimeter in centimetres? (A) 52 (B) 58 (C) 60 (D) 68 (E) 72 www.amt.edu.au

真题文字详解(英文)

40 2022 AMC Upper Primary Solutions

Upper Primary Solutions

1. Two hundred and five thousand, one hundred and fifty is 205 150, hence (E).

2. There are 9 small squares of equal size and 4 are shaded, so the fraction is ( \frac{4}{9} ); hence (D).

3. (Also I) 2220 - 2022 = 198, hence (C).

4. The smallest of the three numbers is 0.08, and the largest is 1.03, hence (B).

5. I am 4 years older than my brother, so I will be 7 + 4 = 11 years old, hence (C).

6. (Also II) Alternative 1 Out of the 29 squares, there are 12 squares that have 3 edges on the perimeter, 4 squares that have 2 opposite edges on the perimeter and 4 squares that have 2 adjacent edges on the perimeter. This accounts for all ( 12 \times 3 + 4 \times 2 + 4 \times 2 = 52 ) edges on the shape, hence (A). Alternative 2 Start with the central 3 x 3 square, with perimeter P = 12. Join the remaining 20 squares one-by-one. Each join increases P by 2: an increase of 4 from the new square but then a decrease of 2 from the join. After joining 20 squares, ( P = 12 + 20 \times 2 = 52 ), hence (A).

7. Between the numbers on the dial the tick marks divide each section into 5 parts, each measuring ( \frac{1}{5} = 0.2 ). So the needle is pointing at 2.4. Since this is in thousands of rpm, it represents ( 2.4 \times 1000 = 2400 \text{rpm} ), hence (E).

8. Since one litre is 1000 mL, there are 1000 - 320 = 680 mL left, hence (C).

9. All these rectangles have an area of 24 square centimetres, hence (E).

10. Jai's morning routine takes 15 + 10 + 20 + 5 + 30 = 80 minutes, which is 1 hour and 20 minutes. To be in school by 8:55 am he should start his shower no later than 7:35 am, hence (A).

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