(1)ξ=3 means touching the red ball three times, so the probability p (ξ = 3) = (3/5) 3 = 27/ 125,

ξ= 1 means that the red ball touched twice and the blue ball touched once, so the probability p (ξ =1) = c (3,2) * (3/5) 2 * (2/5) = 54/125.

ξ=-1 means touching the blue ball twice and the red ball once, so the probability p (ξ =- 1) = c (3,1) (3/5) * (2/5) 2 = 36/65438.

ξ= -3 means touching the blue ball three times, so the probability p (ξ =-3) = (2/5) 3 = 8/ 125,

So the distribution list of ξ is

ξ -3 - 1 1 3

Page 8/125

(2) A leads B 2 points, that is, A scores-1 and B scores-3; Or a 1, b-1; Or a gets 3 points, b gets 1 point,

So the probability is p = (36/125) * (8/125)+(54/125) * (36/125)+(27/125).