Correct answer is 3. Solve the question showing all the steps

Q12. A piece of wax wieghs 18.03 g in air. A piece of metal is found to weigh 17.3 g in water. It is tied to the wax and both together weigh 15.23 g in water. Then, the specific gravity of wax is
 
            $$\begin{gathered} \left(1\right) \frac{18·03}{17·03} \left(2\right) \frac{17·03}{18·03} \\ \left(3\right) \frac{18·03}{19·83} \left(4\right) \frac{15·03}{17·03} \end{gathered}$$