Objective
In this challenge, we practice calculating probability.
Task
Bag contains white balls and black balls. Bag contains white balls and black balls. You draw ball from bag and, without observing its color, put it into bag . Now, if a ball is drawn from bag , find the probability that it is black.
Output Format
In the editor below, submit your answer as Plain Text in the form of an irreducible fraction , where and are both integers.
Your answer should resemble something like:
3/4
(This is NOT the answer, just a demonstration of the answer format.)