2. 1/8 distance around the world, plane 1 transfers 25% of its fuel capacity to plane 2 and 3 and then plane 1 returns to the island

3. 1/4 distance around the world, plane 2 transfers 25% of its fuel capacity to plane 3 and then plane 2 returns to the island

4. Planes 1 and 2 refuel at the island and take off in the opposite direction to which plane 3 is flying.

5. At 1/8 distance around the world, plane 1 transfers 25% of its fuel capacity to plane 2 and then plane 1 returns to the island

6. Plane 2 intercepts plane 3 and transfers fuel to it so that they both have an equal amount of fuel which is 37.5% of their total fuel capacity. Plane 1 and 2 head towards the island. Meanwhile, plane 3 refuels at the island and flies against the direction of which plane 2 and plane 3 are flying in order to intercept them.

7. All 3 planes intercept at a distance of 1/8 the distance around the world. Plane 1 transfers fuel to planes 2 and 3 so that they all have an equal amount of fuel which equals 33.3% of the planes' fuel capacity.

8. All 3 planes return to the island, each with 8.3% fuel left.