After 45 minutes, or one-eighth of the way around, each plane has 135 kiloliters left.

45 分钟后， 即飞行八分之一后，每架飞机还剩下 135 千升。

The key is to maximize the support each assistant provides, not wasting a single kiloliter of fuel.

关键是最大限度地发挥每个助手提供的支持，而不是浪费一公升的燃料。

All three planes take off at noon flying west, each fully loaded with 180 kiloliters.

三架飞机均于中午起飞向西飞行，每架满载180公升。

She gives him 45 kiloliters of her remaining 90, leaving them with 45 each.

她把剩下的 90 瓶中的 45 瓶给他，剩下他们每人 45 瓶。

There's just one problem: the plane can only hold 180 kiloliters of fuel, only enough for exactly half the journey.

只有一个问题：这架飞机只能装 180 公升的燃料，只够飞行一半的路程。

At this point, exactly 180 minutes have passed and the professor is at the halfway point of his journey with 90 kiloliters of fuel left.

此时， 整整 180 分钟过去了，教授正处于行程的中途，还剩下 90 千升燃料。

45 minutes later, just as the other two planes are about to run empty, he meets them at the 315 degree point and transfers 45 kiloliters of fuel to each, leaving 45 for himself.

45 分钟后， 就在另外两架飞机即将空载时，他在 315 度角与他们会合，并给每架飞机转移了 45 公升的燃油， 自己留下 45 公升。