Earth to Neptune is the greatest distance. The number at the top is a power. So 22 to the power 4 is 22 x 22 x 22 x 22 = 234 256. 22 to the power 7 is 22 x 22 x 22 x 22 x 22 x 22 x 22 = 2 494 360 000. It is 22 to the power 3 larger which is 10 648 times greater.
So 2/3 of 36 is 24. So 24 that were filled and 2/3 of 40 is 80/3 which equals 26 2/3 to drain it. And then to fill the pool would be 36 hours. What's so hard...