Math2-http://postimg.org/image/re695knst/?

1a)
First is white, or Second is white, or Third is white, or Fourth is white
X={1,2,3,4}

1b)
P(1)=5/(3+5)=5/8
P(2)=[3/(3+5)][5/(2+5)]=15/56
P(3)=[3/(3+5)][2/(2+5)][5/(1+5)]=5/56
P(4)=1-5/8-15/56-5/56=1/56

2a)
No one is black, or First is black, or Second is black, or Third is black, or Fourth is black
X={0,1,2,3,4}

2b)
(4Cx)(6C5-x)

2c)
P(x)=(4Cx)(6C5-x)/(10C5)

2d)
P(0)=(4C0)(6C5-0)/(10C5)=1/42
P(1)=(4C1)(6C5-1)/(10C5)=5/21
P(2)=(4C2)(6C5-2)/(10C5)=10/21
P(3)=(4C3)(6C5-3)/(10C5)=5/21
P(4)=(4C4)(6C5-4)/(10C5)=1/42

2e)
Total of balls=b+w
P(x)=(bCx)(wCn-x)/(b+wCn)