Consider that the concentration of the medication in the solution is 30 ug/mL.
It means that 1 mL of the solution contains 30 ug of the medication.
So the Unitary Method can be applied to obtain the quantity of solution corresponding to 15 ug of medication, as follows,
[tex]\begin{gathered} \because30\text{ ug of medication}=1\text{ mL of solution} \\ \therefore15\text{ ug of medication}=(\frac{15\times1}{30})=0.5\text{ mL of solution} \end{gathered}[/tex]Thus, 0.5 mL of the liquid solution should be given to the patient.