To solve this problem, we need to determine the formula of the compound formed by elements A and B.$\\$Given:$\\$• Element B forms a cubic close-packed (ccp) structure.$\\$• Atoms of A occupy $\frac{1}{3}$ of the tetrahedral voids.$\\$In a cubic close-packed structure:$\\$• The number of atoms per unit cell of B is 4.$\\$• The number of tetrahedral voids per unit cell is twice the number of atoms, which is 8.$\\$Since atoms of A occupy $\frac{1}{3}$ of the tetrahedral voids:$\\$• Number of A atoms per unit cell $= \frac{1}{3} \times 8 = \frac{8}{3}. \\$The formula of the compound is $A_xB_y. \\$To find the ratio of A to B:$\\$• Number of B atoms per unit cell $= 4. \\$• Number of A atoms per unit cell $= \frac{8}{3}. \\$The ratio of A to B is:$\\ \frac{\frac{8}{3}}{4} = \frac{8}{12} = \frac{2}{3}. \\$Thus, the formula of the compound is $A_2B_3. \\$The value of $x + y$ is:$\\ x + y = 2 + 3 = 5. \\$Therefore, the value of $x + y$ is 5, which corresponds to Option 1.