John and Annie have two distinguishable ponds. Initially, each of the ponds contains four ducks and ve geese. John rst picks a bird uniformly at

John and Annie have two distinguishable ponds. Initially, each of the ponds contains four ducks and five geese. John first picks a bird uniformly at random from the left pond and moves it to the right pond. Then, Annie picks a bird uniformly at random from the right pond.
What is the probability that Annie picks a duck?