Answer: This problem can be solved using the concept of mathematical proportions, the equation that can be constructed for the problem is as follows:
![\begin{gathered} (A_1)/(B_1)=(A_2)/(B_2) \\ \\ \\ (A_(1))/(B_(1))=(150mg)/(225mg) \\ \\ \\ (A_(2))/(B_(2))=(A_2)/(165mg) \\ \\ \therefore\Rightarrow \\ \\ \\ (150mg)/(225mg)=(A_(2))/(165mg)\Rightarrow(1) \end{gathered}](https://img.qammunity.org/2023/formulas/mathematics/college/5ky3d5qs2oznvy4t3ybzbm5k88bdresajc.png)
Solving equation (1) gives the answer, the solution to the equation (1) is as follows:
![\begin{gathered} \begin{equation*} (150mg)/(225mg)=(A_2)/(165mg) \end{equation*} \\ \\ \\ A_2=((150)/(225)*165)mg=110mg \\ \\ A_2=110mg \end{gathered}](https://img.qammunity.org/2023/formulas/mathematics/college/p3mxb5ezbguphk1ooxisb5n5wx61l5l8n0.png)
Therefore the answer is 110mg.