Density is given as mass / volume.
Mass is the sphere is 100 g.
Volume of the sphere = (pi∗r3)∗4/3
(
p
i
∗
r
3
)
∗
4
/
3
=(4∗22∗3∗3∗3)/(7∗3)cm3
=
(
4
∗
22
∗
3
∗
3
∗
3
)
/
(
7
∗
3
)
c
m
3
=792/7
=
792
/
7
cm3
3
Therefore, Density is 100/(792/7)g/cm3
100
/
(
792
/
7
)
g
/
c
m
3
Which gives: density = 0.883838 g/cm3
g
/
c
m
3
If you want to change the units to kg per cubic metres, then we need to divide this value by 1000( for g to kg) and multiply by 100 * 100 * 100 (for cm to m).
This makes the density to be 883.83 kg/m3