题目

You run into the grocery store to pick up one bottle of water. You get what you need, head to the front, and choose the line that looks fastest. You chose wrong. People who you swear got in other lines long after you are already checked out and off to the parking lot. 【1】It turns out, it's just math working against you; chances are, the other line really is faster. Grocery stores try to have enough employees at checkout to get all their customers through with minimum delay. 【2】Any small interruption - a price check, a chatty customer-can have downstream effects, holding up an entire li小明左边口袋中放有三张卡片，上面分别写着1、2、3，他右边口袋中也放有三张卡片，上面分别写着4、5、6，他任意地从两个口袋中各取出一张卡片，则所得两张卡片上写的数之和为偶数的概率是_______________.