A newly married couple decides to continue having children until they have one of each sex. If the events of having a boy and a girl are independent and equiprobable, how many children should this couple expect?
|
A newly married couple decides to continue having children until they have one of each sex. If the events of having a boy and a girl are independent and equiprobable, how many children should this couple expect?
Two, one of each ;)
Three.
The probability for exactly two children is 1/2 (i.e, the chance of the sex of child 2 being different from child 1). The probability of 3 children is (1/2)^2; the probabiliy of four is (1/2)^3 etc. So the expected value is:
| All times are GMT -7. The time now is 03:20 AM. |