Atomic Mass Questions

Among the following, choose the ones with equal number of atoms:A. $212\text{g}$ of ${\text{Na}}_2{\text{CO}}_3$ ($\text{s}$) [molar mass = $106\text{g}$ ]B. $248\text{g}$ of ${\text{Na}}_2\text{O}$ ($\text{s}$) [molar mass = $62\text{g}$ ]C. $240\text{g}$ of $\text{NaOH}$ ($\text{s}$) [molar mass = $40\text{g}$ ]D. $12\text{g}$ of ${\text{H}}_2$ ($\text{g}$) [molar mass = $2\text{g}$ ]E. $220\text{g}$ of ${\text{CO}}_2$ ($\text{g}$) [molar mass = $44\text{g}$ ]Choose the correct answer from the options given below:

Suppose the elements $\text{X}$ and $\text{Y}$ combine to form two compounds ${\text{XY}}_2$ and ${\text{X}}_3{\text{Y}}_2$. When $0.1\text{mole}$ of ${\text{XY}}_2$ weighs $10\text{g}$ and $0.05\text{mole}$ of ${\text{X}}_3{\text{Y}}_2$ weighs $9\text{g}$, the atomic weights of $\text{X}$ and $\text{Y}$ are: