, . ()= NA/N . , .
. . N . , , NA. . mes ( mes = 2 ) mes , ( mes = ) .. |
. . 10 11 , 15 . ?
(10, 10). x- , y .
|x-y|<1/4, 0<x<1, 0<x<1, 0<y<1
() . () mesA 1- (3/4)2 = 7/16. mesW =1, P(A) = 7/16.
. . , . , , . , : . NA , N .
n , .. . .
, , P(A) :
P(A)³0, 2) P(W)=1, 3) P(A1+ +An) = P(A1) + +P(An), A1, An . .
.. , - . .
( ..).
P(A) , , :
1) P(A)³0, "AÎB - W
|
|
2) P(W) = 1
3) : A1, An
P(A1+ +An+ ) = P(A1) + +P(An) +
( ).
, .. ( ) - ( ), .
W , B S . 3 A , A.
(W, B, P).
1) . , , . 3 .
2) P(Æ) = 0. "A A+Æ = A, 3 P(A+Æ) = P(A) + P(Æ) = P(A) ÞP(Æ) = 0
3) AÌ B, P(A) £ P(B). B = A+ B\A, 3 P(B) = P(A) + P(B\A), 1 P(B\A)³0
. 1, 2, 3, 4 ) ) . 1) 111, 2) ?
) , N = 43, 1), NA=1, P = ¼3, 2) NA = , , P = / 43 .
) N = ,1) P = 0, , NA =0, 2) P = 1, N = NA = .
. , . , ?
N = 55. , , 5! = 5!/ 55.
2
.
, . (/) ( , ).
, . , .
. N . NA , NB , N , . . :
, , , . .
:
(2.1)
(2.2)
(2.3)
.
, , . NB ( ), N .
, (2.2) (2.3),
= = (2.4)
. .
. , , .
|
|
. (2.5)
(/) .