In a cubic packed structure of mixed oxides, the lattice is made up of oxide ions, one fifth of tetrahedral voids one occupied by X ions while one half of the octahedral voids are occupied by Y ions. Then formula of the oxide will be

• A

  ${\mathrm{X}}_5{\mathrm{Y}}_4{\mathrm{O}}_{10}$
• Correct answer
  B

  ${\mathrm{X}}_4{\mathrm{Y}}_5{\mathrm{O}}_{10}$
• C

  $\mathrm{X}{\mathrm{Y}}_2{\mathrm{O}}_4$
• D

  ${\mathrm{X}}_2\mathrm{Y}{\mathrm{O}}_4$

Hence, the correct answer is option: 'B'.