MCQ
The probability that a man can hit a target is $\frac{3}{4}$. He tries $5$ times. The probability that he will hit the target at least three times is
- A$\frac{{291}}{{364}}$
- B$\frac{{371}}{{464}}$
- C$\frac{{471}}{{502}}$
- ✓$\frac{{459}}{{512}}$
Therefore required probability
$ = {}^5{C_3}{\left( {\frac{3}{4}} \right)^3}{\left( {\frac{1}{4}} \right)^2} + {}^5{C_4}{\left( {\frac{3}{4}} \right)^4}\left( {\frac{1}{4}} \right) + {}^5{C_5}{\left( {\frac{3}{4}} \right)^5}$
$ = \frac{{10\,.\,27}}{{{4^5}}} + \frac{{5\,.\,81}}{{{4^5}}} + \frac{{243}}{{{4^5}}} = \frac{{270 + 405 + 243}}{{1024}} = \frac{{459}}{{512}}.$
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જ્યાં $\vec u = \,\,x\vec a \, + \;\,2y\vec b ,\,\vec v = \, - 2y\,\,\vec a \,\, + \;\,3x\vec b ,\,\,\vec w \,\, = \,\,4\,\,\vec a \, - \,\,2\,\vec b $ આપેલ છે .