Problem Analysis:
The problem involves understanding the structure of a
binary tree and determining the number of nodes in such a tree based on the given conditions. Here's a breakdown of the key points:
1.
Binary Tree Structure:
- A binary tree is a tree data structure where each node has at most two children, referred to as the left child and the right child.
- The tree has a root node, and every other node is connected by edges.
2.
Given Information:
- There are 8 leaf nodes (nodes with no children).
- Each non-leaf node has exactly two children.
- We need to determine the total number of nodes in the tree.
3.
Key Observations:
- In a binary tree where each non-leaf node has exactly two children, the relationship between the number of leaf nodes (\( L \)) and the total number of nodes (\( N \)) can be derived using the properties of binary trees.
- The number of internal nodes (non-leaf nodes) is always one less than the number of leaf nodes. This is because each internal node contributes to splitting the tree into subtrees, and the structure ensures this balance.
Step-by-Step Solution:
#### Step 1: Define Variables
- Let \( L \) be the number of leaf nodes.
- Let \( I \) be the number of internal nodes.
- Let \( N \) be the total number of nodes in the tree.
From the problem, we know:
\[ L = 8 \]
#### Step 2: Relationship Between Nodes
In a binary tree where each non-leaf node has exactly two children:
- The total number of nodes \( N \) is the sum of leaf nodes \( L \) and internal nodes \( I \):
\[
N = L + I
\]
- The number of internal nodes \( I \) is always one less than the number of leaf nodes \( L \):
\[
I = L - 1
\]
#### Step 3: Substitute Known Values
We know \( L = 8 \). Using the relationship \( I = L - 1 \):
\[
I = 8 - 1 = 7
\]
Now, substitute \( L \) and \( I \) into the equation for \( N \):
\[
N = L + I = 8 + 7 = 15
\]
#### Step 4: Verify the Structure
To ensure the solution is correct, consider the structure:
- With 8 leaf nodes and each internal node having exactly two children, the tree must be a
full binary tree (every internal node has exactly two children).
- The total number of nodes in a full binary tree with \( L \) leaf nodes is indeed \( L + (L - 1) \), which matches our calculation.
Final Answer:
\[
\boxed{15}
\]
Parent Tip: Review the logic above to help your child master the concept of comprehension worksheet for grade 7.
