Question 11
The nation of IMC-land consists of $8$ islands, none of which are connected to each other. Since each citizen wants to visit each of the other islands, the government plans to build bridges between the islands. However, each island has a volcano that could erupt at any time, destroying that island and any bridges that are connected to it. The government wants to guarantee that after any eruption, a citizen from any of the remaining $7$ islands can go on a tour, visiting each of the remaining islands exactly once and returning to their home island (only at the end of the tour). What is the minimum number of bridges needed to be built?