JEE Mains · Maths · STD 12 - 13. probability
Three balls are drawn at random from a bag containing \(5\) blue and \(4\) yellow balls. Let the random variables \(\mathrm{X}\) and \(\mathrm{Y}\) respectively denote the number of blue and Yellow balls. If \(\bar{X}\) and \(\bar{Y}\) are the means of \(X\) and \(Y\) respectively, then \(7 \bar{X}+4 \bar{Y}\) is equal to ..........
- A \(23\)
- B \(26\)
- C \(17\)
- D \(37\)
Answer & Solution
Correct Answer
(C) \(17\)
Step-by-step Solution
Detailed explanation
Blue balls 0 1 2 3 4 5 Pr of blue. \(\frac{{ }^5\text C _0 \cdot{ }^4\text C _1}{{ }^9\text C _3}\) \(\frac{{ }^5\text C _1 \cdot{ }^4\text C _2}{{ }^9\text C _3}\) \(\frac{{ }^5\text C _2 \cdot{ }^4\text C _1}{{ }^9\text C _3}\)…
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