If the crate costs $30 and he wants to make a profit of $110, the total selling value (Income) should be:
![\begin{gathered} \text{Profit}=\text{Income}-\text{Expense} \\ 110=\text{Income}-30 \\ \text{Income}=110+30=140 \end{gathered}](https://img.qammunity.org/2023/formulas/mathematics/college/s5hph2ye23k8298jnwetky04eyzwwa9qb9.png)
Then, if the crate contains 40 blank CD's, in order to find the unitary price of each CD, we can divide the total Income by the number of CD's:
![\text{price}=(140)/(40)=3.5](https://img.qammunity.org/2023/formulas/mathematics/college/j7wnbni9n7lneu7lcrmk5h3s6o6c647vp7.png)
So each CD's should cost $3.50.