25. A box contains 3 yellow balls and 5 black balls. One by one, every ball is selected at random without replacement. What is the probability that the fourth ball selected is black?
1/4
1/2
5/8
2/3
3/4
the answer is 5/8. My doubt is that it asks probability of 4th ball being black so why should we not consider the following cases where the 4th ball is black
YYYB
YYBB
YBBB
BBBB
TIA.
probability
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