Answer:
The mass of A is 4000g.
Step-by-step explanation:
First, divide 28 by 40. Then square root this to get the scale factor between them. (5 over 6). Mass is like volume in this case, so we need to cube 5/6 and then multiply that by 6912 to get the mass of A.
28÷40.32= 25/36
√25/36 =5/6
5/6³ x 6912= 4000g