a) \(\left( \begin{array}{cc} 4 & \{2,3,6,6,7,7,8,9,9\} \\ 5 & \{0,1,1,1,1,1,2,2,4,4,4,4,4,5,5,5,5,6,6,6,7,7,7,7,8\} \\ 6 & \{0,1,1,1,2,4,4,5,8,9\} \\ \end{array} \right)\)
b) just count up the leafs of 5. There are 25 of them
c) just look at the largest leaf of the largest stem. You correctly got 69.