Answer:
[tex]346\ trucks[/tex]
Step-by-step explanation:
1 acre equals to 4840 yard²
So
[tex]3\ acres *\frac{4840\ yard^2}{1\ acre}= 14520\ yard^2[/tex]
Also
[tex]1\ in = 0.02778\ yard[/tex]
So
[tex]24\ in *\frac{0.02778\ yard}{1\ in}= 0.667\ yard[/tex]
So volume V of the contaminated area is:
[tex]V = 14520*0.667\ yard^3\\\\V=9680.48\ yard^3[/tex]
If each truck has a capacity of 28 cubic yards then it is necessary
[tex]9680.48\ yard^3 * \frac{1\ truck}{28\ yard^3}=346\ trucks[/tex]