# 4/15 of the 315 members of a book club are male. How many female members are there in the club?

$231$ members are females
If $\frac{4}{15}$ are the male members of a book club, then $1 - \frac{4}{15} = \frac{11}{15}$ are the female members of a book club
Since we know there are $315$ members, we can go
$\frac{11}{15} \times 315 = 231$