What is the probability of pulling out a red marble then a blue marble?

Answer:
Step-by-step explanation:
Total marble = 8+5+4 = 19
n(Y) = 8, n(B) = 4 and n(R) = 5
Prob(R) = 5/17
Prob(B) = 4/16 {one marble is pulled out already}
Prob(R and B) = 5/17 × 4/16
= 5/17 × 1/4
= 5/68