问题


There is a single choice question about college mathematics. Answer the question by replying A, B, C or D.
Question: A discrete graph is complete if there is an edge connecting any pair of vertices. How many edges does a complete graph with 10 vertices have?
A. 10
B. 20
C. 25
D. 45
Answer:

答案

模型 模型答案 正确答案
金声玉亮2.0

D
D
deepseekr1

The number of edges in a complete graph with \( n \) vertices is given by the combination formula \( \binom{n}{2} \), which calculates the number of ways to choose 2 vertices out of \( n \) to form an edge. This formula simplifies to \( \frac{n(n-1)}{2} \). For \( n = 10 \):

\[
\frac{10 \times 9}{2} = \frac{90}{2} = 45
\]

Thus, a complete graph with 10 vertices has **45 edges**.

Answer: D
D
gpto1 D D
GPT-4o D. 45 D
llama3.1-70B-Instruct

D
D
llama3.1-405B-Instruct

To determine the number of edges in a complete graph with 10 vertices, we can use the formula for the number of edges in a complete graph, which is given by:

Number of edges = n(n-1)/2

where n is the number of vertices.

Plugging in n = 10, we get:

Number of edges = 10(10-1)/2
= 10(9)/2
= 90/2
= 45

Therefore, the correct answer is:

D. 45
D
DeepSeek-Coder-V2 D. 45 D
Qwen2-72B-Instruct D. 45 D
baichuan4 D. 45 D
doubao D. 45. For a complete graph with n vertices, the number of edges is n(n-1)/2. For a graph with 10 vertices, the number of edges is 10(10-1)/2 = 45. D
minimax D. 45

A complete graph with n vertices has an edge between every pair of vertices. The number of edges in a complete graph can be calculated using the formula for combinations, since each edge is a combination of 2 vertices from the set of n vertices:

Number of edges = n(n - 1) / 2

For a complete graph with 10 vertices:

Number of edges = 10(10 - 1) / 2
= 10 * 9 / 2
= 90 / 2
= 45

So, the correct answer is D. 45.
D
kimi The number of edges in a complete graph can be calculated using the formula for combinations, since each edge is a combination of 2 vertices out of the total number of vertices. The formula for combinations is:

\[ \text{Number of combinations} = \frac{n!}{k!(n-k)!} \]

For a complete graph, \( n \) is the total number of vertices and \( k \) is the size of the combination (which is 2 for an edge). So the formula simplifies to:

\[ \text{Number of edges} = \frac{n(n-1)}{2} \]

For a graph with 10 vertices:

\[ \text{Number of edges} = \frac{10 \times (10-1)}{2} = \frac{10 \times 9}{2} = \frac{90}{2} = 45 \]

Answer: D. 45
D
wenxinyiyan D. 45

Explanation:
In a complete graph with n vertices, there is an edge connecting every pair of vertices. To count the number of edges, we can use the formula for combinations:
C(n, 2) = n * (n - 1) / 2
This formula gives the number of ways to choose 2 items from n items without repetition, which corresponds to the number of edges in a complete graph.
Using n = 10, we get:
C(10, 2) = 10 * (10 - 1) / 2 = 10 * 9 / 2 = 45
So, a complete graph with 10 vertices has 45 edges.
D
zhipu To determine the number of edges in a complete graph with \( n \) vertices, we use the formula:

\[ \text{Number of edges} = \frac{n(n-1)}{2} \]

For a complete graph with 10 vertices (\( n = 10 \)):

\[ \text{Number of edges} = \frac{10(10-1)}{2} = \frac{10 \times 9}{2} = \frac{90}{2} = 45 \]

Therefore, the correct answer is:

D. 45
D
gpto1 D D
deepseekv3 To determine the number of edges in a complete graph with 10 vertices, we use the formula for the number of edges in a complete graph with \( n \) vertices:

\[
\text{Number of edges} = \frac{n(n - 1)}{2}
\]

For \( n = 10 \):

\[
\text{Number of edges} = \frac{10 \times 9}{2} = \frac{90}{2} = 45
\]

Therefore, the correct answer is:

D. 45
D