A coin is biased so that heads comes up thrice as likely as tails. In four independent tosses of the coin, what is probability of getting exactly three heads ?
- A$\frac{81}{256}$
- B$\frac{27}{64}$
- C$\frac{27}{256}$
- D$\frac{9}{256}$
✓ Correct answer: B
Want the full step-by-step reasoning?