On an island there are 7 cities. Each two of them connected by a direct road. How many roads are there?

21 roads

Step-by-step explanation:

If each two cities are connected by a direct road, to find the number of roads we just need to solve a combination of 7 choose 2, that is, we need to find all pairs of two cities among the 7 cities:

Combination of 7 choose 2 = 7! / (5! * 2!) = 7*6/2 = 21

So there is a total of 21 roads on the island.

ok so the answer to your question is simple as long as you look at the different dimensions that contain the exemplary letters that combined in the right order give you words that eventually within the 5th dimension will conform and give you the correct answer to your question. hope i , stop looking at this easily, look at it with a spectral view.

step-by-step explanation:

told you

answer: 0

step-by-step explanation: the positive, like 5, + its opposite, like -5 would be 0

5+(-5)=0, or 5-5=0