I keep finding an answer for Q12 that isn't on your list of possibilities... The surface area of the moon is 14,658,000 sq miles, that of the earth 196,879,339 sq miles. That means that the earth's surface is 13.5 times the surface of the moon.
[edited to add:]
The formula for the surface area of a sphere is 4*pi*r^2. Since you're comparing two area's, you can leave out the 4*pi, so you end up comparing the square radius.
The moon's diameter is 3480 km, that makes it's radius 1740 km. The earth's diameter is 12,750 km, giving a 6375 km radius. If you calculate (6375*6375)/(1740*1740) it will lead to the answer 13.4233799.
[edited a second time to correct a typo]