Suppose a box contains $5$ indistinguishable white balls and $2$ indistinguishable black balls. What is the probability that a selected ball from the box is white?
This question certainly appears trivial. If the balls were all distinguishable, the answer would have been $5/7$. However, what would the answer be if balls of the same colour are indistinguishable?
If the answer remains $5/7$, why is the answer independent of whether balls of the same colour are distinguishable or not?