(2009•天河区一模)如图,正六边形的游戏盘被分成6个面积相等的三角形,每一个三角形都标有相应的数字.甲乙两人按一定的
1个回答

(1)∵除了负数就是正数就这两种情况,∴P(正数)=

3

6=

1

2;

(2)根据题意,画表格或画树状图或列举法说明均可,

乙 1 2 3 -1 -2 -3

1 (1,1) (2,1) (3,1) (-1,1) (-2,1) (-3,1)

2 (1,2) (2,2) (3,2) (-1,2) (-2,2) (-3,2)

3 (1,3) (2,3) (3,3) (-1,3) (-2,3) (-3,3)

-1 (1,-1) (2,-1) (3,-1) (-1,-1) (-2,-1) (-3,-1)

-2 (1,-2) (2,-2) (3,-2) (-1,-2) (-2,-2) (-3,-2)

-3 (1,-3) (2,-3) (3,-3) (-1,-3) (-2,-3) (-3,-3)由上图可知,点(x,y)的坐标共有36种等可能的结果,

其中点(x,y)落在第一象限的共有9种,

所以,P(点(x,y)落在第一象限)=

9

36=

1

4.