<em>solution</em><em> </em><em>:</em><em>-</em><em>-</em>
 
        
             
        
        
        
Answer:
x = 7
Step-by-step explanation:
I used the formula c^2 = a^2 + b^2
if you need further explanation,let me know
 
        
             
        
        
        
This question has this set of answer choices:
a) when the plane cuts three faces of the cube, separating one corner from the others 
b) when the plane passes through a pair of vertices that do not share a common face
c) when the plane is perpendicular to the base and intersects two adjacent vertical faces
d) when the plane makes an acute angle to the base and intersects three vertical faces
e) not enough information to answer the question
The right answer is the first choice: a) when the plane cuts three faces of the cube, separating one corner from the others 
You can see a picture of this case in the figure attached: as you can see the cross section (in pink) is a triangle.
 
        
        
        
There are 151,200 possible combinations. If you'd like an explanation of my answer, please let me know.
        
             
        
        
        
We can set up a proportion.
32/128 = x/100
32 * 100 = 3200
128 * x = 128x.
Now we have 128x = 3200.
All we need to do is divide 3200 by 128, so 3200 / 128 = 25, so your answer is 25%.