## Discussion Forum

Que. | Consider an undirected graph G where self-loops are not allowed. The vertex set of G is {(i, j): 1 <= i <= 12, 1 <= j <= 12}. There is an edge between (a, b) and (c, d) if |a − c| <= 1 and |b − d| <= 1. The number of edges in this graph is __________. |

a. | 500 |

b. | 502 |

c. | 506 |

d. | 510 |

Answer:506 |