JEE Mains · Maths · STD 12 - 13. probability
A bag contains \(4\) red and \(6\) black balls. A ball is drawn at random from the bag, its colour is observed and this ball along with two additional balls of the same colour are re turned to the bag. Ifnow a ball is drawn at random from the bag, then the probability that this drawn ball is red, is :
- A \(\frac{2}{5}\)
- B \(\frac{1}{5}\)
- C \(\frac{3}{4}\)
- D \(\frac{3}{{10}}\)
Answer & Solution
Correct Answer
(A) \(\frac{2}{5}\)
Step-by-step Solution
Detailed explanation
Let \(R_{t}\) be the even of drawing red ball in \(t^{\text {th }}\) draw and \(B_{t}\) be the event of drawing black ball in \(t^{\text {th }}\) draw. Now, in the given bag there are \(4\) red and \(6\) black balls. \(P\left(R_{1}\right)=\frac{4}{10}\) and…
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