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Probability problem of ninth grade mathematics
1.( 1) Solution: Because it is random to put three balls in which box, there are six kinds.

The color combinations of the balls in the three boxes are red, white, blue, red, blue, white, red, blue, red, blue, white and red.

(2) Solution: The probability of putting the red ball into each box is the same, and * * * has three boxes.

Therefore, the probability that the red ball can just fit into box 2 is P= 1/3.

Second, the solution: put the lid on the teacup in turn. The first teacup and lid have two combinations, and the second teacup has only one.

Therefore, * * has 2x 1=2 (species).

In both cases, only one collocation is correct and the probability of each collocation is the same.

Therefore, the probability of correct color matching is P= 1/2.