今天我们给出第七组袋鼠竞赛的题目（每个年级组一道题），并给出第六组题目（见《袋鼠数学竞赛题选（六）》）的解答。

1-2年级组

Which pattern can we make using all five cards given below?

使用所给的5张卡片，可以摆出哪个选项中的图案？

3-4年级组

Magic trees grow in a magic garden. Each tree contains either 6 pears and 3 apples or 8 pears and 4 apples. There are 25 apples in the garden. How many pears are there in the garden?

魔术花园里种了一些魔法树。每棵树上要么结6个梨子和3个苹果，要么结8个梨子和4个苹果。已知花园里共有25个苹果，那么花园里共有多少个梨子？

5-6年级组

The number 2581953764 is written on a strip of paper. John cuts the strip 2 times and gets 3 numbers. Then he adds these 3 numbers. Which is the smallest possible sum he can get?

一张纸条上写了一个数2581953764。John把纸条剪了两刀，剪成3截。他把三截纸条上的三个数相加，所得的和数最小可能是多少？

7-8年级组

Ivor writes down the results of the quarter-finals, the semi-finals and the final of a knock-out tournament. The results are (not necessarily in this order): Bart beat Antony, Carl beat Damien, Glen beat Henry, Glen beat Carl, Carl beat Bart, Ed beat Fred and Glen beat Ed. Which pair played in the final?

Ivor记录了一场淘汰赛的四分之一决赛、半决赛和决赛的结果。他记录的结果如下（不一定按照比赛顺序）：Bart战胜Antony，Carl战胜Damien，Glen战胜Henry，Glen战胜Carl，Carl战胜Bart，Ed战胜Fred，Glen战胜Ed。请问，哪两个人在决赛中对阵？

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下面是第六组题目的参考答案和解析。

1-2年级组

In Baby Roo's house, each room is connected to any neighboring room by a door as shown in the picture. Baby Roo wants to get from the room A to the room B. What is the least number of doors that he will need to go through?

在Baby Roo的房子里，每个房间和与它相邻的房间之间都有一扇门相连，如下图。Baby Roo想从房间A走到房间B。他最少需要经过多少扇门？

3-4年级组

Three ropes are laid down on the floor as shown. You can make one big, complete loop with three other pieces of rope. Which of the ropes shown will give you one big loop?

三条绳子如下图那样放置在地板上。你可以利用另外三条绳子，与这三条绳子一起构成一个大的绳圈。你可以用下面哪组绳子做到？

需要特别注意的是，如果绳子的数量超过3根，则第一段中的结论不成立。比如4条绳子，有可能是形成两个小的绳圈，每个绳圈都由4根绳子（2根是原来的绳子，2根是选项中的绳子）构成。

5-6年级组

A train has 12 coaches. Each coach has the same number of compartments. Mike is travelling in the third coach and in the 18th compartment from the engine. Jane sat in the 7th coach in the 50th compartment from the engine. How many compartments are there in each coach?

一列火车有12节车厢，每节车厢里有相同数量的隔间。Mike位于第三节车厢，坐在从火车头数过来的第18个隔间。Jane位于第七节车厢，坐在从火车头数过来的第50个隔间。每节车厢里有多少个隔间？

【答案：B】根据Jane的隔间编号，可知每节车厢应该有8个隔间。如果每节车厢的隔间数少于8，第50个隔间应该出现在第7节车厢之后（7×7=49）；如果每节车厢的隔间数大于8，第50个隔间应该出现在第7节车厢之前（6×9=54）。

7-8年级组

Two pieces of rope have lengths 1 m and 2 m. Alex cuts the pieces into several parts. All the parts have equal lengths. Which of the following could not be the total number of parts he obtains?

两条绳子的长度分别为1米和2米。Alex把它们剪成小段，每段绳子都一样长。下面哪个数不可能是他得到的绳子的段数？

【答案：B】由于每段绳子都一样长，所以第二根绳子剪出的段数应该是第一根绳子的2倍。从而，所有绳子的数量应该是3的倍数。所有选项中，只有（B）的数不是3的倍数。