JEE Mains · Maths · STD 12 - 13. probability
Two dice \(A\) and \(B\) are rolled, Let the numbers obtained on \(A\) and \(B\) be \(\alpha\) and \(\beta\) respectively. If the variance of \(\alpha-\beta\) is \(\frac{p}{q}\), where \(p\) and \(q\) are coprime, then the sum of the positive divisors of \(p\) is equal to
- A \(36\)
- B \(48\)
- C \(31\)
- D \(72\)
Answer & Solution
Correct Answer
(B) \(48\)
Step-by-step Solution
Detailed explanation
\(\sum\left( x ^2\right)=\sum x ^2 P ( x )=2\left[\frac{25}{36}+\frac{32}{36}+\frac{27}{36}+\frac{16}{36}+\frac{5}{36}\right]\) \(=\frac{105}{18}=\frac{35}{6}\) \(\mu=\sum(x)=0\) as data is symmetric…
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