A bag contains 11 balls which are identical except 5 are numbered balls and 6 are blank. The 5 numbered balls are labelled 1, 2, 3, 4, and 5. You randomly select 4 balls without replacement. You cannot see into the bag and each ball in the bag is equally likely to be selected. Calculate the probability that all 4 balls taken are numbered, given that the ball numbered '3' is removed first. Write your answer in the form $, where a, b E Z, a 2 0, b > 0 and god(a, b) = 1. Enter a. Enter b