Answer:
the answer is 19 but I feel like it wrong hope it helps
Because what your doing is breaking apart the dividend to make it easy to divide with the divisor.
Example 189/3
What you do is place value in hundreds would be
180/3= 60
9/3=3 add together you get 63
You can find the volume by using the formula of density

where d is the density, m is the mass and v is the volume
You have to solve the formula for v like this:

you have the density and the mass so you just have to replace the variables in the formula with the values they are giving you, like this:

The volume of the stone is 7ml
The first one: 56
The second one: 100
The third one: 144