# What is the probability that first is yellow and second is blue?

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There are 4 blue and 8 yellow balls.
Two balls are selected one by one without replacement.
What is the probability that first is yellow and second is blue?

posted Jul 9, 2019

67% and 33%
.
Of the 12 balls 8 are yellow =? 8/12 = 67%
.
For the second ball the color of the first ball is unknown.
So there is
67% chance that of the 11 balls 4 are blue = 0.5 * 4/11 = 18%
and 33% chance that of the 11 balls 3 are blue = 0.5 * 3/11 = 14%
Total chance = 33%

answer Jul 9, 2019 by

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