Answer:
(a) 1 to 8
(b) 1 to 6
Step-by-step explanation:
A "leaf" is a node at the end of a binary tree (in other words, it has no "children"). All other nodes are "non-leaf" nodes.
The smallest number of leaves is 1. That would be a binary tree that's just a straight line; each node will have only 1 child, until you get to the last node (the leaf).
To find the largest number of leaves, we start drawing a full binary tree. A complete tree with 15 nodes has 7 non-leaf nodes and 8 leaf nodes. A full tree with 6 non-leaf nodes can have up to 6 leaf nodes.