Answer:
A=density=1.42g/cm^3
mass=9.94g
volume=7cm^3
B=density =?
mass=128.66g
volume=125cm^3
C=density=108g/cm^3
mass=138.6g
volume=132cm^3
massA 1.42×7=9.94g
massB 138.6-9.94=128.66g
massC 132×1.05=138.6g
Density of B =mass/ volume
=126.66÷ 125
= 1.03g/cm^3