- #1
synkk
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Two coins are flipped and the results are recorded. Given that one coin lands on a head, find the probability of:
a) Two heads, b) a head and a tail
Searching online is giving my answers which are not using conditional probability at all, and our teacher told us we have to use the formulas etc, but i keep getting it incorrect.
Well i haven't attempted b as i can't do a but here is my working:
Let a be the coin that lands on heads
Let b be the unknown coin
so P(B | A) = P(B and A) / P(A)
P(A) = 1/2
P(B) = 1/2
P(B and A) = 1/4
P(B | A) = 1/4 / 1/2 = 1/2 which is obviously wrong.
To be honest i think P(A) is correct but i don't know how to do P(B).
a) Two heads, b) a head and a tail
Searching online is giving my answers which are not using conditional probability at all, and our teacher told us we have to use the formulas etc, but i keep getting it incorrect.
Well i haven't attempted b as i can't do a but here is my working:
Let a be the coin that lands on heads
Let b be the unknown coin
so P(B | A) = P(B and A) / P(A)
P(A) = 1/2
P(B) = 1/2
P(B and A) = 1/4
P(B | A) = 1/4 / 1/2 = 1/2 which is obviously wrong.
To be honest i think P(A) is correct but i don't know how to do P(B).