Answer:
3.5g/ml or 3.5g/cm³
Step-by-step explanation:
1cm³=1ML
Volume of the irregular shaped stone = New Volume of water in cylinder -initial Volume of water in cylinder
Volume of irregular shaped stone = 8ml-2ml
Volume of irregular shaped stone =6ml
Denisty =Mass/Volume
Density = 21g/6ml
Density = 3.5g/ml