Must Be True—Formal Logic. The correct answer choice is (E)
Formal logic questions can be very intimidating for some test takers. However, by diagramming carefully and drawing appropriate inferences, most formal logic mistakes can be easily avoided. Consider each statement individually and then jointly to determine any additive inferences.
- SC = small country
SH = southern hemisphere
PS = permanent seat on the United Nations Security council
The contrapositive of this statement is:
- IP = increased international peacekeeping
MR = greater role in moderating regional disputes
- ISR = increased spending on refugees
The next step is to find common terms in multiple statements and combine the statements to draw additional inferences. IP is common to both the second and third statements, but the “some” condition of the third statement prevents us from linking it to the second statement. The third statement cannot be used to conclude anything about the permanent members of the UN Security Council
(PS IP ISR does not yield any inferences). This is an important inference and will be tested in answer choice (C).
PS is common to the second statement and the contrapositive of the first statement. Combining these two statements produces:
This inference can be stated in a number of ways, including, “Some countries that are in favor of a greater role for the United Nations in moderating regional disputes are not located in the southern hemisphere.” Thus, answer choice (E) is correct.
Answer choice (A): All that is known about small countries is that they do not have permanent seats on the United Nations Security Council. This information about small countries cannot be linked to any conclusion about their position on refugee spending.
Answer choice (B): Again, one can only know that no country in the southern hemisphere is permanently on the Security Council. It cannot be known whether any of these countries are in favor of or against increased international peacekeeping efforts. This answer choice could be confusing if it were read as, “Some countries in favor of increased international peacekeeping efforts are not in the southern hemisphere,” as that is proven true by the stimulus, but that is not what this answer choice states.
Answer choice (C): It has already been shown that any attempt to draw a conclusion about countries with a permanent seat on the UN Security Council based on the facts of the third statement is invalid. All five countries with permanent seats on Security Council are in favor of increased international peacekeeping efforts and may also be in favor of increased spending on refugees.
Answer choice (D): This answer choice is incorrect for the same reasons that answer choices (A) and (B) are incorrect. The information provided about small countries does not support any inferences about their positions on any of the other topics mentioned in the stimulus.
Answer choice (E): This is the correct answer choice. From the stimulus, one can correctly infer that there are at least five countries (i.e. all the members of the Security Council with permanent seats) that are both in favor of a greater role for the United Nations in moderating regional disputes and are not located in the southern hemisphere.