Answer
53506.2 kg
Work Step by Step
We can write,
Buoyant force + Buoyant force on balloon = weight of the container
on container
$(F_{B})_{C}+(F_{B})_{B}=mg$
Since the container & the balloon are fully submerged in the water, by using the Archimedes principle, we can rewrite the above equation,
$V_{C}\rho_{w}g+V_{B}\rho_{w}g=mg$
$m=\rho_{w}(V_{C}+V_{B})$ ; Let's plug known values into this equation.
$m=(1025\space kg/m^{3})[(6.1)(2.4)(2.6)m^{3}+\frac{4}{3}\pi (1.5\space m)^{3}]=53506.2\space kg$
Mass of the container = 53506.2 kg
