At the end of the year, Wilson's Department Store awards free merchandise to its top salespeople. When presented with...

JennaArthur November 20, 2019

How common are strengthen questions with sufficient condition?

I was wondering how often these types of questions appear as it seems that I am worse at these questions than any of the other strengthening questions. Logical Reasoning is soup and I am a fork!

Create a free account to read and take part in forum discussions.

Already have an account? log in

SamA November 25, 2019

Hello @Kaitlyn,

I wish I could give you some better data, but from my own experience I would say that these are not particularly common. I would expect 1 or 2 on your test. However, I believe that you can learn to master them quickly. In my opinion, strengthen with necessary premise is the more difficult of the two.

You may have seen the video lesson already, but I'll give you a brief explanation of how to approach them. Then, with enough practice, you can become a spork, the official utensil of LSATMax.

"Would allow the conclusion to be properly drawn" or "justifies the conclusion" are indicators of a strengthen with sufficient question. Notice the absence of necessary indicators such as "must be assumed," "necessary assumption," or "depends on."

In this case, our answer choice needs to completely guarantee the conclusion. Unlike strengthen with necessary assumption questions, in which the too strong answer is often wrong, we want our answer to be as strong as possible! We want to be certain that the conclusion will follow. Just think of your basic sufficient and necessary statements. The sufficient condition guarantees the necessary condition. In this case, the conclusion is necessary, and we must find the sufficient premise.

Let's look at your example.

Premise: The number of salespeople receiving awards has declined in the last 15 years.
Premise: Currently, the top third of the sales force gets the awards.
Conclusion: The number of people who don't get awards have also declined.

Under current conditions, the sales force has two parts: award winners (1/3) and non-winners (2/3). Because these are constant proportions, one group cannot decrease without the other group decreasing. Under these conditions, the conclusion is correct! However, something is missing. We don't know if the criterion have always been the same. If they have changed in the last 15 years, then the conclusion is not valid. Answer choice C gives us the sufficient premise that was missing. This, in addition to the premises given in the argument, guarantees the conclusion.