Puzzles/Physics puzzles/Flying around the World

Puzzles | Physics puzzles | Flying around the World

You intend to fly around the world starting from an island with any amount of identical planes and an indefinite supply of fuel. Each of the planes can go exactly half around the world with one supply of fuel. Planes flying next to each other can exchange any amount of fuel which takes no time. Also turning around and refueling takes no time for a plane.

Given that you cannot land any plane anywhere but on the island and no plane is to be crashed, what is the minimum amount of planes that you need to take one of them around the world?

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