Video Explanation

Text Explanation

Let’s assume for simplicity that there are 100 professors, so we can treat the percents as ordinary numbers.   This will lead to the same answer.

We will use a double matrix.  Here’s the blank matrix setup.

Of these 100 professors, 60 are academic professors, so the rest are professional professors.  

The next piece of information is interesting: “90% of the professors at Paracelsus University are academic professors or tenured or both.”  Those people are represented by these boxes:

The four central boxes have to add up to everyone, 100.  If those three constitute 90 people, then we know 10 people must be left in the single white box.  

We know 40 are in the “Professional” row: if 10 are in the right box, then 40 − 10 = 30 must be the left box.

There are 40 professional professors, and 30 of them are tenured.  That’s or 75%.

Answer = (E)

Extra information you do not need to know for the test: the name of the University comes from an intellectual luminary of the Renaissance, Paracelsus (1492-1541), a physician and alchemist.  He is known as the "father of toxicology" and probably was the person who named the element zinc.  Paracelsus said, "The art of medicine has its roots in the heart," and "Nothing is hidden so much that it wouldn't be revealed through its fruits."