Ignoring twins and other mutiple births, assume babies born at a hospital are independent events with the probability that a baby is a boy and the probability that a baby is a girl both equal to 0.5. Referring to the information above, the probability that at least one of the next three babies are of the same sex is...?

Question

I don't know how to approach this problem. Please help!

Answer 1

For these types of problems, I like drawing a probability tree.

That said, I really don't understand your question. With 3 babies, at least 2 will be of the same sex (BBG or BGG) possibly all 3 are the same sex (BBB or GGG). Could you clarify?

Answer 2

Is this a trick question? "One" cannot be the same sex. It takes at least two to be the same.

I hope this helps a little more. Thanks for asking.