isit correct , like the steps and the answers because I'm not really sure

for #2 the volume of a cube is V=S^3
so it V= 8^3 = 512cubic cm
m = 5.6/512 = 0.011 kg/cm^3
#3 is correct
question 2 the volume of a cube is V=S^3. question 3 is right is correct. nice handwriting btw