1)
Root - top node of a structure
Child - nodes lower then another in the hierarchy
Leaf - a node at the end of the tree
Parent -  a node higher just above the current node
Ancestor - a node somewhere above the current in the tree
Sub-tree - tree inside the main tree

2) You need 17 levels to store 100,000 nodes.

3) a) 1-min and 15 max
   b) 7 min and 7 max

8) It counts the number of leaves.

public class exercises
{
  public boolean isLeaf(TreeNode node)
  {
    return node.getLeft() == null && node.getRight() == null;
  }
  public int sumTree(TreeNode root)
  {
    if(root == null)
      return 0;
    int sum = 0;
    sum += (Integer)root.getValue();
    sum += sumTree(root.getLeft());
    sum += sumTree(root.getRight());
    return sum;
  }
  public int countPaths(TreeNode root)
  {
    int sum = 0;
    if(root.getLeft() != null)
    {
      sum++;
      sum += countPaths(root.getLeft());
    }
    if(root.getRight() != null)
    {
      sum++;
      sum += countPaths(root.getRight());
    }
    return sum;
  }
  public int depth(TreeNode root)
  {
    if(root == null)
      return 0;
    int d = 1;
    return Math.max(d + depth(root.getLeft()),
                    d + depth(root.getRight()));
  }
}