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Sarah has 1 red cube, 1 green cube, 1 purple cube, and 1 black cube. If Sarah picks two items from the bag, without replacing, what is the probability she will pick a red cube and then a black cube?

User Daveman
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1 Answer

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Given:

Sarah has 1 red cube, 1 green cube, 1 purple cube, and 1 black cube.

Sarah picks two items from the bag without replacement.

We need to determine the probability that she will pick a red cube and then a black cube.

Probability:

The probability to pick a red cube is
P(R)=(1)/(4)

The probability to pick a black cube without replacement is
P(B)=(1)/(3)

The probability to pick a red cube and then a black cube is given by


P(RB)=P(R) \cdot P(B)

Substituting the values, we have;


P(RB)=(1)/(4) \cdot (1)/(3)


P(RB)=(1)/(12)

Thus, the probability that Sarah will pick a red cube and then a black cube is
(1)/(12)

User Huliax
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