Answer
Please see the work below.
Work Step by Step
We know that
$volume=\frac{mass}{density}$
We plug in the known values to obtain:
$volume \space of \space crucible =\frac{860.2}{21.45}=40.10cm^3$
Now $Volume \space of\space water \space displaced=\frac{(860.2-820.2)}{0.9986}=40.1cm^3$
