JEE Mains · Maths · STD 12 - 13. probability
Bag 1 contains 4 white balls and 5 black balls, and Bag 2 contains \(n\) white balls and 3 black balls. One ball is drawn randomly from Bag 1 and transferred to Bag 2. A ball is then drawn randomly from Bag 2. If the probability, that the ball drawn is white, is \(29 / 45\), then \(n\) is equal to :
- A 6
- B 3
- C 5
- D 4
Answer & Solution
Correct Answer
(A) 6
Step-by-step Solution
Detailed explanation
Bag \(1 \rightarrow 4 w, 5 B\) Bag \(2 \rightarrow n w, 3 B\) \((\mathrm{I}) \rightarrow\) Transferred ball is white \(P(w)=\frac{n+1}{n+4} \cdot \frac{4}{9}\) (II) \(\rightarrow\) Transferred ball is black \(P(w)=\frac{5}{9} \cdot \frac{n}{n+4}\)…
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