(a)
Prob 0 green = 5C3 / 9C3 = .12
Prob 1 green = 3C1 * (4/9)(5/9)^2 = .41
Prob 2 green 3C2 * (4/9)^2 * (5/9) = .33
Prob 3 green = (4/9)^3 = .09
The last histogram is correct
(b)
Expected number of green balls
0*(.12) + 1*(.41) + 2*(.33) + 3*(.09) = 1.34