(Answer:
P(Bl or Yl) = 45%
(Pk on 2nd draw) = 18%
Step-by-step explanation:
There are a total of 20 marbles (3 + 4 + 5 + 8) in the bag. Since each marble is replaced once drawn, there is no change in the total count from one draw to another (unconditional probability).
So
P(Bl or Yl) = (5 + 4)/20 = 9/20 = .45 = 45%
Then
P(Pk on 2nd draw) = P(1st draw) * P(2nd draw)
= 9/20 * 8/20 = 72/400 = 9/50 = .18 = 18%