(1)由题意知X的可能取值为0,2,10,
P(X=10)=
=
C
C
,1 15
P(X=2)=
=
C
C
,3 15
P(X=0)=1-
?1 15
=3 15
,11 15
∴X的分布列为:
X | 0 | 2 | 10 | ||||||
P |
|
|
|
11 |
15 |
3 |
15 |
1 |
15 |
16 |
15 |
1 | ||
|
1 |
15 |
| ||
|
1 |
5 |
1 |
15 |
1 |
5 |
4 |
15 |
P(A) |
P(A+B) |
| ||
|
1 |
4 |