A division problem always seems simple until a fraction is thrown in, right? Thought it may look more than a simple division problem, it really is a simple division problem that needs a shift in your mental perspective.
Let's start off by simplifying the horrid mixed fraction.
2 11/16 = (32 + 11)/16 = 43/16
Now divide "30" by "43/16".
[tex] \frac{30}{1} [/tex] x [tex] \frac{16}{43} [/tex]
You may be thinking, "Wait, that's a multiplication problem!" Actually, when dividing fractions you are essentially multiplying the dividend by the reciprocal (flip) of the divisor.
[tex] \frac{480}{43} = 11\frac{7}{43} [/tex]
Since every book is of equal width, and we cannot cut into any books, 11 books can fit in the shelf. Hope this helps!