A fair coin is tossed 6 times. Given that at least 2 heads occurred, the probability of exactly 3 heads is:
Answer and explanation
Correct answer: B.
- Step 1: .
- Step 2: .
- Step 3: .
Answer
.
Why not the others: ignores the condition; and use the wrong conditioning event, since is and is .
Practise more Probability, Binomial and Normal Distributions.
Free questions with an explanation for every one, and full timed Victorian VCE mock tests.
More Probability, Binomial and Normal Distributions questions
- The random variable has a binomial distribution . The standard deviation of is:
- Let . Given that , find .
- A discrete random variable has probability function for . Find the exact value of .
- Given that events and are independent with and , find .
- The weights of newborn puppies are normally distributed with mean and standard deviation . If of puppies…
- A continuous random variable has probability density function for , and elsewhere. Calculate…