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 :
Answer & explanation
Correct answer: option 1
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
$≡{^4C}_2(\frac{4}{5})^2(\frac{1}{5})^2=\frac{6×16}{625}=\frac{96}{625}$