In a certain zoo, rabbits are kept in the hut which looks like the form as shown in Fig. 1 when it is seen from right above.
In the inside of the hut, there are transparent boards at the position of the dotted line in the figure and it is divided into eight rooms.
The shadow portion in the middle is not a room.
There are four windows in the hut and we can see rabbits by looking through the windows.
For example, when rabbits are kept as shown in Fig. 2, four rabbits are visible from any window and there are nine in total.
(1) There may be a room in which no rabbit is.
Rabbits should be kept to be seen nine from any window.
In this case, how many rabbits are there at least and how many rabbits at most?
(2) There is at least one rabbit kept in every room and 17 rabbits in total are kept in the hut.
In order for 7 rabbits to be seen from any window, how many rabbits should be kept in each room?
Answer one pattern in the figure.
For example, when putting in a rabbit as shown in Fig. 2, it should be answered as shown in Fig. 3.
In the inside of the hut, there are transparent boards at the position of the dotted line in the figure and it is divided into eight rooms.
The shadow portion in the middle is not a room.
There are four windows in the hut and we can see rabbits by looking through the windows.
For example, when rabbits are kept as shown in Fig. 2, four rabbits are visible from any window and there are nine in total.
(1) There may be a room in which no rabbit is.
Rabbits should be kept to be seen nine from any window.
In this case, how many rabbits are there at least and how many rabbits at most?
(2) There is at least one rabbit kept in every room and 17 rabbits in total are kept in the hut.
In order for 7 rabbits to be seen from any window, how many rabbits should be kept in each room?
Answer one pattern in the figure.
For example, when putting in a rabbit as shown in Fig. 2, it should be answered as shown in Fig. 3.
Answer
(1) 18 rabbits at least, 36 at most
(2) Examples of answers
(2) Examples of answers
Reference
(1)
(2)
