Question

A biased coin lands heads with probabilty 2/3. The coin is tossed 3 times
a) Given that there was at least one head in the three tosses, what is the probability that there were at least two heads?
b) use your answer in a) to find the probability that there was exactly one head, give that there was at least one head in the three tosses.
It asks me to solve it using sequences of events. I have tried solving it but with no luck. Please help me
Thanks

Thanks

Answer 1

there are eight possible sequences for three tosses

HHH , HHT , HTH , THH , HTT , THT , TTH , TTT

look at the descriptions of the sequences , and count the relevant outcomes