Q11 - In early 1990, Queenston instituted a tax increase tha

by **charmayne.palomba** Tue Nov 01, 2011 4:19 pm

PT46, S3, Q11 (Inference)

(B) is correct.

"Which of the following must be true" lets us know we are dealing with an inference question, in which it’s our job to identify the answer choice that is most provable, based on a given set of facts. (Remember to be careful not to confuse these questions with strengthen questions"”inference questions are not part of the assumption question family, so no need to search for a core or a conclusion, because most of the time you’ll do so in vain).

Let’s start by listing what we know:

1. Because of a budget increase, the school system increased its total number of teachers by 30% between 1990 and 1993.
2. In that same period of time, there was no change in the average number of students per teacher.

That seems surprising, right? You would expect that an increase in teachers would be enough to reduce class size. How can we explain this unexpected result? This question relies on your understanding of ratios. For example, the ratio of law students and business students at a cocktail party is 2:1, and 4 more law students show up but the ratio doesn’t change, what can we infer? The new ratio needs to be 6:3. So 2 new business students need to join the party. The same goes for the school system. If we know the student to teacher ratio remains the same despite the addition of more teachers, what has to have happened to the number of students? It must have increased. (B) hits the nail on the head!

Now let’s look at what we can’t infer:

(A) This is the opposite of what we’re looking for! If average class size remained the same while the number of teachers increased, enrollment in some classes had to have increased, otherwise average class size would have declined.

(C) Out of scope. All we know is that the budget increase was enough to increase the number of teachers by 30%. With the same amount of money, maybe they could have decided to increase the number of teachers by 60% and pay them less, or choose to use the money for something else altogether. We know nothing about the amount of the budget increase, so we can eliminate this answer. Don’t be intimidated by numbers!

(D) Out of scope again! Who cares whether they were the same teachers or different ones? We only care about the change in the number of teachers between 1990 and 1993, not who they are.

(E) Quality of education? Totally out of scope!