Topic: Discrete Mathematics
If there are five faces and nine vertices in an undirected planar graph, then number of edges is
- A. 14
- B. 16
- C. 12
- D. None of the above
Answer: C. 12
Explanation: Euler's formula for a connected planar graph is $V - E + F = 2$. Given Vertices ($V$) = 9 and Faces ($F$) = 5. Substituting the values: $9 - E + 5 = 2 \implies 14 - E = 2 \implies E = 12$.