Mathematics - Probability Question with Solution | TestHub

MathematicsProbabilityTotal probability/Bay's TheoremEasy2 minPYQ_2019

MathematicsEasysingle choice

An urn contains $5$ red and $2$ green balls. A ball is drawn at random from the urn. If the drawn ball is green, then a red ball is added to the urn and if the drawn ball is red, then a green ball is added to the urn; the original ball is not returned to the urn. Now, a second ball is drawn at random from it. The probability that the second ball is red, is:

Options:

Answer:

Solution:

Let $A$ is event that $2 n d$ drawn ball is red.

$∴ P (A) = P (R) \times P (A / R) + P (G) \times P (A / G)$

$= \frac{5}{7} \times \frac{4}{7} + \frac{2}{7} \times \frac{6}{7}$

$= \frac{32}{49}$

Stream:JEESubject:MathematicsTopic:ProbabilitySubtopic:Total probability/Bay's Theorem

⏱ 2mℹ️ Source: PYQ_2019

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