Quick solution to the mathematical probability problem in senior high school: six college students volunteers from two universities, A and B, were randomly and evenly assigned to three positions, A, B and C (see supplement). 1) only look at position a, and the total selection method is c (6,2) =15.

Neither of them is a university. C (x, 2) = 15 * (1-3/5) = 6 kinds.

X=4, that is, 4 people are from University B and 2 people are from University A..

2) Same as 1, p = c (4, 1) c (2,1)/c (6,2) = 8/15.

3) The distribution lists of the three locations are exactly the same, and he directly draws a conclusion from the first two questions.

ξ=0 P=2/5

ξ= 1 P=8/ 15

ξ=2 P= 1/ 15

Eξ=2/3