Question

Approximately 71% of the Earth’s surface is water. The total surface area of the Earth is approximately 5.1 x 1014 m2. How many square meters of the Earth’s surface is not water? Assuming that people could occupy only the land part of the Earth, approximately when would people be so crowded that every person would have only 1 m2 of space?

Answer 1

71% water means 29% not water, so 0.29 * 5.1*10^14 m^2
when there are that many people, each would have only 1 m^2 of space, right?