Two important ores of metals are given below
Malachite $\mathrm{C}\mathrm{u}\mathrm{C}{\mathrm{O}}_3.\mathrm{C}\mathrm{u}(\mathrm{O}\mathrm{H}{)}_2.\mathrm{x}{\mathrm{H}}_2\mathrm{O}$
Carnallite $\mathrm{K}\mathrm{C}\mathrm{l}.\mathrm{M}\mathrm{g}\mathrm{C}{\mathrm{l}}_2.\mathrm{y}{\mathrm{H}}_2\mathrm{O}$
What is $\mathrm{y}‐\mathrm{x}?$

Hence, the correct answer is 6.