Question

According to the American Medical Association, one-third of all twins are identical, and the other two-thirds are fraternal. All identical twins are (obviously) same-sex, but the sex of fraternal twins is determined independently, as with other, non-twin siblings. Assuming that male and female children are equally likely, what is the probability that a randomly chosen set of same-sex twins is identical?

a. 0.75 b. 0.6667 c. 0.25 d. 0.3333 e. 0.5

Answer 1