作业帮（英文）麻烦解释原因.Amy has to visit towns B and C in any order. The roads connecting these towns with her home are shown on the diagram. How many different routes can she take starting from A and returning to A, going through both B and C
来源：学生作业帮助网 编辑：作业帮 时间：2024/11/30 15:35:57
（英文）麻烦解释原因.Amy has to visit towns B and C in any order. The roads connecting these towns with her home are shown on the diagram. How many different routes can she take starting from A and returning to A, going through both B and C
（英文）麻烦解释原因.
Amy has to visit towns B and C in any order. The roads connecting these towns with her home are shown on the diagram. How many different routes can she take starting from A and returning to A, going through both B and C (but not more than once through each) and not travelling any road twice on the same trip?
（英文）麻烦解释原因.Amy has to visit towns B and C in any order. The roads connecting these towns with her home are shown on the diagram. How many different routes can she take starting from A and returning to A, going through both B and C
①顺时针绕椭圆一圈
②逆时针绕椭圆一圈
③将弧AC换为向椭圆内凸的路线,顺时针
④路线同上,逆时针
⑤将弧CB换为向椭圆内凸的路线,顺时针
⑥路线同上,逆时针
⑦将弧AC、BC均换为向椭圆内凸的路线,顺时针
⑧路线同上,逆时针
综上,There're 8 different routes that she can take.
我理解的意思就是从A~B~C~A一共有几条不同的路线，我设的是先到C再到B，
那是有5条，因为先到B再到C走法一样，所以都给排除掉了。
8条
There are four routines for her to spin counterclockwise around the circle.
1.AC(outside)-CB(outside)-BA
2.AC(outside)-CB(inside)--BA
3.AC(inside)--CB(inside)--BA
4.AC(inside)--CB(...
全部展开
There are four routines for her to spin counterclockwise around the circle.
1.AC(outside)-CB(outside)-BA
2.AC(outside)-CB(inside)--BA
3.AC(inside)--CB(inside)--BA
4.AC(inside)--CB(outside)--BA
There are four routines for her to go clockwise around the circle.
1.AB-BC(outside)-CA(outside)
2.AB-BC(inside)-CA(outside)
3.AB-BC(outside)-CA(inside)
4.AB-BC(inside)-CA(inside)
In conclusion,we can say there are 8 routines for her from A retuning to A .
收起
去尚友SAT论坛看看，希望能找到你要的~