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AP EAMCET · Maths · Probability

An urn contains 3 black and 5 red balls. If 3 balis are drawn at random from the urn, the mean of the probability distribution of the number of red balls drawn is

  1. A \(\frac{45}{28}\)
  2. B \(\frac{15}{8}\)
  3. C \(\frac{2}{5}\)
  4. D \(\frac{3}{2}\)
Verified Solution

Answer & Solution

Correct Answer

(B) \(\frac{15}{8}\)

Step-by-step Solution

Detailed explanation

Let \(X\) be number of red balls drawn. \begin{array}{|c|c|c|c|c|}\hline \boldsymbol{X}=\boldsymbol{x} & 0 & 1 & 2 & 3 \\\hline \boldsymbol{P}(\boldsymbol{X}=\boldsymbol{x}) & \frac{{ }^3 C_3}{{ }^8 C_3} & \frac{{ }^5 C_1 \times{ }^3 C_2}{{ }^8 C_3} & \frac{{ }^5 C_1 \times{ }^3…