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?

#### Solution

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.