Ok so first just pay attention to the Mystery books and Science books.
there are 13 mystery books and 15 Science books so your answer will be two.
Hope this helps.
Answer:

Step-by-step explanation:
Substitute x=2 into f(x) x times 3

Calculate it

The intersecting chords theorem states that whenever two chords intersect, the product of their pieces is constant.
So, in this case, we have

Plugging your values, we have

This equation has solutions
, but we can't choose
, because it would lead to

So, the only feasible solutions is 
Answer:
E = 324
Step by step explanation: