## Discrete Mathematics with Applications 4th Edition

a. $15$ b. $0$
$$n=dq+r=d(n\ div\ d)+n\ mod\ d$$ $$30=2(30\ div\ 2)+30\ mod\ 2=2(15)+0$$ The numbers $n\ div\ d$ and $n\ mod\ d$ are defined to be the numbers $q$ and $r$, respectively, as given in the quotient-remainder theorem. See page 181 of the text.