What volume of liquid ${\mathrm{A}}_2{\mathrm{O}}_3$ has same number of atoms as there are atom in having volume 20 ml? [Given : Density of ${\mathrm{A}}_2{\mathrm{O}}_3=1.5\mathrm{gm}/\mathrm{ml}$ and density of ${\mathrm{BO}}_2=0.7\mathrm{gm}/\mathrm{ml}$ Atomic mass of A = 50, Atomic mass of B = 60 and O represents oxygen]