Brain Teasers and Puzzles

How Many Daughters

A mother randomly selected two of her children to pick up a package from the post office. There was a 50% chance both children were daughters. How many daughters does this mother most likely have?


3 daughters, out of 4 children total.

If she had d daughters and c children, that means the probability she picked two daughters is (d / c) * (d – 1)/(c – 1) = 0.5. This means she could have 3 daughters out of 4 children, or she could have 15 daughters out of 21 children, and so on. However, it’s much more likely she has 4 children than 21 or more children.

Leave a Reply

Your email address will not be published. Required fields are marked *