Answer: Last option.
Step-by-step explanation:
The total amount of concrete in the ramp ([tex]V_t[/tex]) will be the sum of the volume of the rectangular prism ([tex]V_{rp}[/tex]) and the volume of the triangular prism ([tex]V_{tp}[/tex])
[tex]V_t=V_{rp}+V_{tp}[/tex]
The formulas are:
[tex]V_{rp}=lwh[/tex]
Where "l" is the lenght, "w" is the width and "h" is the height.
[tex]V_{tp}=\frac{bhl}{2}[/tex]
Where "l" is the lenght, "b" is the base and "h" is the height.
Substituting, we get:
[tex]V_t=V_{rp}+V_{tp}\\\\V_t=lwh+\frac{bhl}{2}\\\\V_t=(18in)(6in)(6in)+\frac{(8in)(6in)(18in)}{2}\\\\V_t=1,080in^3[/tex]
