ExamBro
ExamBro
TS EAMCET · Maths · Probability

If \(\mathrm{X} \sim \mathrm{B}(7, \mathrm{p})\) is a binomial variate and \(\mathrm{P}(\mathrm{X}=3)=\mathrm{P}(\mathrm{X}=5)\) then \(\mathrm{p}=\)

  1. A \(\frac{5-\sqrt{10}}{3}\)
  2. B \(\frac{\sqrt{10}-2}{3}\)
  3. C \(\frac{5-\sqrt{15}}{2}\)
  4. D \(\frac{\sqrt{15}-3}{2}\)
Verified Solution

Answer & Solution

Correct Answer

(C) \(\frac{5-\sqrt{15}}{2}\)

Step-by-step Solution

Detailed explanation

\(\binom{7}{3} \mathrm{p}^3 (1-\mathrm{p})^4 = \binom{7}{5} \mathrm{p}^5 (1-\mathrm{p})^2\) \(35 \mathrm{p}^3 (1-\mathrm{p})^4 = 21 \mathrm{p}^5 (1-\mathrm{p})^2\) \(35 (1-\mathrm{p})^2 = 21 \mathrm{p}^2\) \(5 (1-2\mathrm{p}+\mathrm{p}^2) = 3 \mathrm{p}^2\)…