MHT CET · Maths · Probability
If \(X \sim B\left(8, \frac{1}{2}\right)\), then \(P(|x-4| \leq 2)=\)
- A \(\frac{119}{128}\)
- B \(\frac{29}{128}\)
- C \(\frac{238}{728}\)
- D \(\frac{119}{228}\)
Answer & Solution
Correct Answer
(A) \(\frac{119}{128}\)
Step-by-step Solution
Detailed explanation
We have \(\mathrm{n}=8, \mathrm{p}=\frac{1}{2} \quad \Rightarrow \mathrm{q}=\frac{1}{2}\)
To find \(\mathrm{P}(|\mathrm{X}-4| \leq 2) \quad \Rightarrow \mathrm{X}=2,3,4,5,6\)
Hence required probability
\(={ }^{8} C_{2}\left(\frac{1}{2}\right)^{6}\left(\frac{1}{2}\right)^{2}+{ }^{8} C_{3}\left(\frac{1}{2}\right)^{5}\left(\frac{1}{2}\right)^{3}+{ }^{8} C_{4}\left(\frac{1}{2}\right)^{4}\) \(\left(\frac{1}{2}\right)^{4}+{}^{8} C_{5}\left(\frac{1}{2}\right)^{3}\left(\frac{1}{2}\right)^{5}+{ }^{8} C_{6}\left(\frac{1}{2}\right)^{2}\left(\frac{1}{2}\right)^{6} \)
\( =\left(\frac{1}{2}\right)^{8}\left[{ }^{8} C_{2}+{ }^{8} C_{3}+{ }^{8} C_{4}+{ }^{8} C_{5}+{ }^{8} C_{6}\right] \)
\( =\frac{1}{256}[28+56+70+56+28]=\frac{238}{256}=\frac{119}{128}\)
To find \(\mathrm{P}(|\mathrm{X}-4| \leq 2) \quad \Rightarrow \mathrm{X}=2,3,4,5,6\)
Hence required probability
\(={ }^{8} C_{2}\left(\frac{1}{2}\right)^{6}\left(\frac{1}{2}\right)^{2}+{ }^{8} C_{3}\left(\frac{1}{2}\right)^{5}\left(\frac{1}{2}\right)^{3}+{ }^{8} C_{4}\left(\frac{1}{2}\right)^{4}\) \(\left(\frac{1}{2}\right)^{4}+{}^{8} C_{5}\left(\frac{1}{2}\right)^{3}\left(\frac{1}{2}\right)^{5}+{ }^{8} C_{6}\left(\frac{1}{2}\right)^{2}\left(\frac{1}{2}\right)^{6} \)
\( =\left(\frac{1}{2}\right)^{8}\left[{ }^{8} C_{2}+{ }^{8} C_{3}+{ }^{8} C_{4}+{ }^{8} C_{5}+{ }^{8} C_{6}\right] \)
\( =\frac{1}{256}[28+56+70+56+28]=\frac{238}{256}=\frac{119}{128}\)
See the Complete Solution
Get step-by-step explanations for this and 2.5 Lakh+ more JEE, NEET & CET questions.
- Unlock all solutions
- Practice the full chapter
- Track accuracy across PYQs
4.8 rated on Google Play · 14,000+ reviews
More questions from Maths
- If \(A^{-1}=\left[\begin{array}{lll}3 & 2 & 6 \\ 1 & 1 & 2 \\ 2 & 5 & 5\end{array}\right]\), then \(A=\)MHT CET 2021 Medium
- The function f defined by \(\mathrm{f}(x)=(x+2) \mathrm{e}^{-x}\) isMHT CET 2025 Medium
- If \(\sin ^{-1}(4 x)+\sin ^{-1}(4 \sqrt{3} x)=-\frac{\pi}{2}\), then the absolute value of \(x\) isMHT CET 2025 Medium
- Which of the following quantified statement is true?MHT CET 2016 Easy
- A ladder of length \(17 \mathrm{~m}\) rests with one end against a vertical wall and the other on the level ground. If the lower end slips away at the rate of \(1 \mathrm{~m} / \mathrm{sec}\)., then when it is \(8 \mathrm{~m}\) away from the wall, its upper end is coming down at the rate ofMHT CET 2023 Hard
- The equation \(x^2-3 x y+\lambda y^2+3 x-5 y+2=0\), where \(\lambda\) is real number, represents pair of lines. If \(\theta\) is acute angle between the lines, then \(\frac{\operatorname{cosec}^2 \theta}{\sqrt{10}}=\)MHT CET 2025 Medium
More PYQs from MHT CET
- Let \({ }^{\prime} \mathrm{R}_{1}\) ' and \({ }^{\prime} \mathrm{R}_{2}\) ' are radii of two mercury drops. A big mercury drop is formed from
them under isothermal conditions. The radius of the resultant drop isMHT CET 2020 Medium - \(\int \frac{\sin x+\sin ^3 x}{\cos 2 x} \mathrm{~d} x=\mathrm{A} \cos x+\mathrm{B} \log \mathrm{f}(x)+\mathrm{c}\)
(where \(\mathrm{c}\) is a constant of integration). Then values of A, B and \(\mathrm{f}(x)\) areMHT CET 2023 Hard - If \(2 \cos ^{2} \theta+3 \cos \theta=2\), then permissible value of \(\cos \theta\) isMHT CET 2020 Easy
- What is the time needed to reduce the initial concentration of reactant to \(10 \%\) in a first order reaction if its half life time is 10 minutes?MHT CET 2024 Easy
- Which of the following rules states that it is impossible to determine simultaneously the exact position and exact momentum of an electron?MHT CET 2024 Medium
- There are two samples \(A\) and \(B\) of a certain gas, which are initially at the same temperature and pressure. Both are compressed from volume v to \(\frac{\mathrm{v}}{2}\). Sample A is compressed isothermally while sample B is compressed adiabatically. The final pressure of \(A\) isMHT CET 2024 Medium