Question

check my answer please:

When three fair coins are tossed, calculate the conditional probability that two heads and a tail turn up, given that first coin came up heads.

P(A) is that 2 heads and 1 tail
P(B) is 1 one is heads.
since we are considering that first one is going to be heads, then P(a) is 1 head and 1 tail?

so (1/4) / (1/2)

Answer 1

` given that first coin came up heads.`

so we don't have to factor this in. We just need to consider the other two coins

Answer 2

P(second one is heads) = 1/2
P(third one is tails) = 1/2


P(second one is heads AND third one is tails) = P(second one is heads)*P(third one is tails)
P(second one is heads AND third one is tails) = (1/2)*(1/2)
P(second one is heads AND third one is tails) = 1/4

Answer 3

okay.. and if we do that means we are calculating the event happening twice which is not what we want .. yea?

Answer 4

thanks!