JEE Mains · Maths · STD 12 - 13. probability
Three rotten apples are accidently mixed with fifteen good apples. Assuming the random variable \(x\) to be the number of rotten apples in a draw of two apples, the variance of \(x\) is
- A \(\frac{37}{153}\)
- B \(\frac{57}{153}\)
- C \(\frac{47}{153}\)
- D \(\frac{40}{153}\)
Answer & Solution
Correct Answer
(D) \(\frac{40}{153}\)
Step-by-step Solution
Detailed explanation
\(3\) bad apples, \(15\) good apples. Let \(\mathrm{X}\) be no of bad apples Then \(P(X=0)=\frac{{ }^{15} C_2}{{ }^{18} C_2}=\frac{105}{153}\) \({P}(\mathrm{X}=1)=\frac{{ }^3 \mathrm{C}_1 \times{ }^{15} \mathrm{C}_1}{{ }^{18} \mathrm{C}_2}=\frac{45}{153}\)…
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