b) 47 : 3 71 : 4 92 : 5

b)

           $\begin{array}{l}\begin{array}{c}47\\ \underset{¯}{3}\end{array}\begin{array}{c}3\\ 15\end{array}\\ 17\\ \underset{¯}{15}\\ 02\end{array}$                                           $\begin{array}{l}\begin{array}{c}71\\ \underset{¯}{4}\end{array}\begin{array}{c}4\\ 17\end{array}\\ 31\\ \underset{¯}{28}\\ 03\end{array}$                                  $\begin{array}{l}\begin{array}{c}92\\ \underset{¯}{5}\end{array}\begin{array}{c}5\\ 18\end{array}\\ 42\\ \underset{¯}{40}\\ 02\end{array}$          

47 : 3 = 15 (dư 2)                                 71 : 4 = 17 (dư 3)                       92 : 5 = 18 (dư 2)