If two fair coins are flipped and at least one of the outcomes is known to be…
2011
If two fair coins are flipped and at least one of the outcomes is known to be a head, what is the probability that both outcomes are heads?
- A.
1/3
- B.
1/4
- C.
1/2
- D.
2/3
Attempted by 94 students.
Show answer & explanation
Correct answer: A
Since we know one outcome is head, there are only three possibilities {h, t}, {h, h}, {t, h}
The probability of both heads = 1/3