there are a total of 5+4=9 fish
P(catfish)=59
there are now a total of 8 fish, 4 are catfish
P(second catfish)=48=12
there are now 7 fish, 3 are catfish
P(third catfish)=37
P(fourth catfish)=26=13
P(fifth catfish)=15
to calculate the probability of catching 5 catfish
multiply the separate probabilities together
⇒P(5 catfish)=59×12×37×13×15=151890