A coin is biased so that head is 4 times as likely to occur as tails. If X represents the number of heads when coins is tossed 4 times then P(X=2) is equal to : |
$\frac{96}{625}$ $\frac{9}{256}$ $\frac{27}{625}$ $\frac{18}{625}$ |
$\frac{96}{625}$ |
The correct answer is Option (1) → $\frac{96}{625}$ P(Head) = 4 P(Tail) $⇒P(H)=\frac{4}{5}$ and $P(T)=\frac{1}{5}$ so $P(X=2)$ for $n=4$ tosses $≡{^4C}_2(\frac{4}{5})^2(\frac{1}{5})^2=\frac{6×16}{625}=\frac{96}{625}$ |