Step-by-step explanation:Turn 0.4 into a fraction. It equals 4/10. Then do 4/10 time 1/10. To get the answer do 4 times 1. Then do 10 times 10. 4 times 1 equals 4 and 10 times 10 equals 100. 4/100 is the final result, so the answer is 4/100.
The formula for the surface area of a sphere is 4r². The variable is the radius. Therefore, the sphere with the smallest radius would have the smallest surface area.
