Matrix multiplication

In a concert, the numbers of performers in three age groups are represented by
$P = \begin{bmatrix}12 & 18\\20 & 10\\8 & 14\end{bmatrix}$, where the rows are Singing, Dancing and Acting, and the columns are Children and Teens.

The registration fees are $F = \begin{bmatrix}15 & 20\end{bmatrix}$, in dollars for Children and Teens respectively.

Using matrix multiplication, find the total registration fees collected for Acting.