What is the ratio of the surface area of a cube to the surface area of a rectangular solid identical to the cube in all ways except that its length has been doubled?
Any idea how to solve these guys?
30 second approach:
A cube has 6 faces, suppose each has an area of 1, so surface area of the cube will be 6;
A rectangular solid identical to the cube in all ways except that its length has been doubled
is just complicated way of saying that the rectangular solid is built with two cubes, hence it has 4+4+2=10 faces of a little cube (just imagine to cubes put one on another) and thus the surface area of the rectangular solid will be 10;
why "4+4+2" if there are two cubes than it should be "4+4" = 8 faces