Hello!
You have to find the area of the prism and the pyramid
rectangular prism is lwh
Put in the values you know
15 * 5 * 7 = 525
For a prism you use

Put in the values you know

Multiply
975/3
Divide
325
Add the values you know
325 + 525 = 850
The answer is D)

Hope this helps!
For this case we have the following equation:

Let 
We have:

By definition, given an equation of the form 
The quadratic formula, to find the solution can be written as:

In this case we have:

Substituting in the quadratic formula we have:
See attached image
Answer:
Option B
The sample space is nothing but ALL possible outcomes. In this case you have Black & Red id's. Then the sample space is {black, red}
18cm is the answer of this question
I would have to say 32,4 but i would double check it