A box contains 4 yellow balls and 6 black balls. One by one, every ball is selected at random without replacement. What is the probability that the fourth ball selected is black? Pick one:
A) 2/3  B) 1/2  C) 5/8  D) 3/5  E) 3/4
Each ball has an equal chance (1/10) of being selected fourth.   The probability that a black ball is selected fourth is 6/10 = 3/5.   The answer is 3/5.
<result>D</result>
A box contains 4 yellow balls and 6 black balls. One by one, every ball is selected at random without replacement. What is the probability that the fourth ball selected is black?