Can you me with my question! i'm desperate! it's due for monday: is it possible to remove ten unit cubes from a 3 by 3 by 3 cube made from 27 unit cubes so that the surface area of the remaining solid is the same as the surface area of the original 3 by 3 by 3 cube? in how many different ways can this be done?you! i'd really appreciate if you could ! xx

I observed that if I remove one (or all 8) piece(s) in the corners, and only them without adjacent ones, the total area does not change.

I consider the surface area of a small square as a unit of surface.

First class of solutions:

I removed all eight corners, leaving the total area unchanged.

I removed the central cube of the top surface obtaining an increase of the surface area with four units.

I removed one cube from the middle of an edge at the top (any of the four remaining) and I arrived at a figure with ten cubes less then the original one but with the same surface area.

(There's a lot more solutions here: https://nrich.maths.org/787/solution)

Planet earth has a mass of 5.9726x10²⁴ kg.then: 5.9726x10²⁴ kg=100% of the total earth mass.if the water´s mass=5x10-4 % of the total mass, we can solve this problem by the rule of three.5.9726x10²⁴ %*10⁻⁴ %x=(5.9726x10²³ kg)(5*10⁻⁴  %) / 100 %=2.9863x10¹⁹ kganswer:   the mass of the planet´s water would be   2.9863 x 10¹⁹ kg.