To find the volume of a rectangular prism, you can use the formula:
\[ \text{Volume} = \text{Base Area} \times \text{Height} \]
In this case, the base area is 15 square units and the height is 5 units.
Plugging in the values:
\[ \text{Volume} = 15 , \text{units}^2 \times 5 , \text{units} = 75 , \text{units}^3 \]
So, the volume of the rectangular prism is 75 units cubed.