2023 袋鼠数学 B-Ecolier 真题 答案 详解

中英双语真题

MATH KANGAROO CHINA Math Kangaroo 2023 (China)-Level B 3 points 1. Akira lights 5 identical candles all at the same time. They stopped burning at different times and now look as shown in the picture. Which candle stopped burning first? 小安将5支相同的蜡烛同时点燃。蜡烛在不同的时间停止燃烧，现在看起来如图所示。 哪支蜡烛最先停止燃烧？ (A) A (B) B (C) C (D) D (E) E 2. The 2 kangaroo coins with the question mark on have the same value. What is this value? 标注问号的两枚袋鼠硬币的面值相同。它们的面值是多少？ 20 + 10 + 10 + ? + ? + 1 = 51 (A) 1 (B) 2 (C) 5 (D) 10 (E) 20 3. A gray circle with 2 large holes in it is put on top of a clock-face, as shown. 如图所示，将带有两个孔的灰色圆盘放在钟面上。 The gray circle is turned around its center. 灰色圆盘绕其中心旋转。 Which 2 numbers is it possible to see at the same time? 哪两个数字可能同时被看到？ (A) 4 and 9 4 和 9 (B) 5 and 9 5 和 9 (C) 5 and 10 5 和 10 (D) 6 and 9 6 和 9 (E) 7 and 12 7 和 12