The key is to realize that the volume never changes. The formula for the volume of a sphere is (4/3)*pi*radius^3 22/7 is being substituted in place of pi in this problem The volume of one of the small spheres is (4/3)*(22/7)*2^3 is about 33.524 cm^3 64 of those spheres would have a volume of 33.524*64, or about 2145 cm^3 Now, the problem is to find a sphere with a volume of 2145 cm^3 Volume = (4/3)*(22/7)*radius^3 plug in and solve 2145 = 4.1905*r^3 r^3=511.87 r is about equal to 8.2 centimeters
