Logical Reasoning Problem Set #1, Question #46

[ronnieronnie]

Hi Guys,

I am having trouble understanding how answer choice B is not outside the scope of the question. Where does saving other animals' lives and human lives come in from the stimulus. I selected answer choice D.

Thanks,
Ronnie

[Dave Killoran]

Hey Ronnie,

This is another all-time classic question, and this one also features conditional reasoning (it doesn't need to be diagrammed, but you do need to recognize that it is present in the answer). Let's start by looking at part of the stimulus.

In the first line it is stated that Mary is a veterinary student. I italicized "student" because if you look at (D), it applies to practicing veterinarians, not veterinary students. If that difference wasn't there, (D) would be pretty attractive. But, it is there, so this doesn't apply to Mary.

Now let's look at (B) in conjunction with the stimulus. Answer choice (B) is conditional in nature (see the "unless"), and can be diagrammed as:

Taking life justified immediately assist in saving several animal lives or protecting health

Well, from the stimulus, would the assignment immediately assist in saving several animal lives? No. Would it protect the health of a person? Also no. So, the necessary condition is not met, which means that, via the contrapositive, taking the life is not justified. That's exactly what Mary decided to do here in not doing the assignment, so her decision accords with this principle.

Please let me know if that helps. Thanks!