Overview: Strengthen & Weaken | Verbal for GMAT PDF Download

Introduction

Both strengthen and weaken questions ask you to find a new piece of information that if added to the existing argument will make the conclusion either: more likely to be true (strengthen) or less likely to be true (weaken).

Strengthen Questions

• These questions will have the words “strengthen” or “support” and “if true”

Example:

• Which of the following, if true, most strengthens the argument?
• Which of the following, if true, most strongly supports the author’s claim?

How to Approach

Excavations in the summer of 2008 at the sites of Hohle Fels and Vogelherd revealed nearly a complete paleolithic ivory bone flute. This flute is by far the most complete of all of the musical instruments thus far recovered from the caves of Swabia. These finds demonstrate the presence of a well-established musical tradition at the time when modern humans colonized Europe, more than 35,000 calendar years ago.

Because the discovered ivory bone flute has 5 holes in it, enough to play 5 notes from the 7-note diatonic scale, musicologists believe that the diatonic musical scale was developed and used thousands of years before it became popular during the Renaissance period in Western Europe.

Which of the following, if true, most strongly supports the hypothesis?

(A) Bone flutes were probably the only musical instrument made by Swabian cavemen.
(B) The mammoth tusk bone used to make the Swabian flute would have been long enough to make a flute capable of playing a complete diatonic scale.
(C) No musical instrument that is known to have used a diatonic scale is of an earlier date than the flute found in the Swabian cave.
(D) Flutes are the simplest wind instrument that can be constructed to allow playing a diatonic scale.
(E) The flute was made from a mammoth bone and the site at which the flute fragment was excavated was in a cave that also contained skeletal remains of wooly mammoths.

Upon reading the passage, many may find it confusing as it alternates between discussing the flute and a "well-established musical tradition," touching on the flute's holes and something about a musical scale. To navigate this, the recommended GMAT Pill 3-step Approach can be employed: 1) Identify the conclusion, 2) Visualize the question, and 3) Pre-think the answer. Following these steps, you can efficiently handle such problems in real-time with practice.

Step 1: Identify the Conclusion
Typically found at the passage's end, the conclusion follows a structure like "Because X, so Y." Here, X supports Y. In this case, X is the flute having 5 holes, and Y is the diatonic musical scale developed many years ago.

Step 2: Visualize the Question
This is an observation -> conclusion scenario. Visually, it connects the conclusion closely with the support, indicated by the sentence structure ("because X, therefore Y").

Step 3: Pre-think the Answer
The connection is established between "flute holes" and the "musical scale" through the passage. The link is that "holes" correspond to "notes," providing a connection between the flute and the musical scale.

Now, let's consider the answer choices:

(A) Not relevant. Talks about the flutes being the only instruments made but doesn't establish a connection between a 5-hole flute and a complete musical scale.
(B) Yes. Suggests the flute could originally have had 7 holes, making the connection between "flute holes" and a "complete diatonic scale" stronger.
(C) Not relevant. Discusses the absence of earlier flutes with a diatonic scale but doesn't connect a 5-hole flute specifically to a musical scale.
(D) Not relevant. Mentions the ease of making a scale with a flute but doesn't show how a 5-hole flute is associated with a musical scale.
(E) Not relevant. States the flute was made from mammoth bone, but the bone's origin isn't linked to the musical scale.

By pre-thinking and expecting an answer choice that strengthens the connection between "flute holes" and the "musical scale," it becomes clear that choices A, C, D, and E are not relevant. This approach helps save time by quickly recognizing irrelevant answer choices without reading them thoroughly, contributing to more efficient problem-solving during the GMAT.

Weaken Questions

• Begin by examining the question stem to understand it's a weaken question.
• Analyze the stimulus to identify the conclusion and how it's supported by the premises.
• Scrutinize the reasoning for any gaps, flaws, or shifts in the subject between the premises and conclusion.
• Look for answer choices that specifically target the identified weaknesses in the stimulus.
• If the stimulus lacks apparent weaknesses, seek an option introducing new information that allows the premises to be true while casting doubt on the conclusion.
• Ensure that, while assessing options, their scope aligns with the premises and the qualifications of the conclusion. For instance, if the conclusion concerns animal suffocation, options discussing poisoning should be considered irrelevant.

Example:

Increasingly, American businesses requiring customer service phone lines have been utilizing overseas companies that can provide these services at extremely reduced rates. Toll-free calls are routed to countries like India, where low-paid workers have been trained to deal with most of the typical problems consumers have with their credit cards, online services, and computer equipment. Since the companies using these overseas call centers are saving so much money, they will undoubtedly show higher profits than companies that do not.

Which of the following, if true, most seriously weakens the argument?

(A) There is strong competition among overseas call centers to provide the most comprehensive services at the lowest rates.
(B) Consumers opposed to exporting American jobs are willing to pay more for goods and services from companies that don't engage in this practice.
(C) Certain banking services cannot be outsourced, since this would require the release of customer financial data.
(D) Because offshore telephone customer service companies provide only these services, they can train their employees more thoroughly than American companies could.
(E) Some American companies send their own employees overseas to train the call center personnel in their particular business.

Solution:

When dealing with weaken questions, like the one presented here, begin by following the steps employed for assumption questions. Initially, identify the author's conclusion, which, in this case, asserts that companies relocating their call centers abroad will yield higher profits than those that do not.

Subsequently, pinpoint the supporting evidence for the conclusion. In this argument, the term "since" serves as the evidence, indicating that companies achieve cost savings by outsourcing their call centers.

Next, seek the assumption, the implicit connection between the conclusion and evidence. In this scenario, the assumption lies in the belief that moving a call center overseas does not adversely affect gross revenues.

Lastly, since this is a weaken question, the objective is to find an answer choice that challenges the assumption. In this instance, option (B) accomplishes this by suggesting that companies utilizing American labor may command higher prices for their products. Consequently, the cost savings from moving call centers overseas might not necessarily lead to higher profitability compared to retaining call centers in the United States and increasing product prices.

Skills to Solve Strengthening and Weakening Questions

Once you've become skilled at pinpointing the main assumption in a critical reasoning problem, the next crucial skill is figuring out how to make an argument stronger or weaker. Strengthen and weaken questions are more common on the GMAT than assumption questions, so being adept at identifying ways to strengthen or weaken an argument is vital for getting most critical reasoning questions right.

• To strengthen an argument, look for the answer choice that confirms the central assumption is correct. This can happen in two ways. 
• First, the correct answer might basically restate the assumption. If an answer choice would be right for an assumption question, it's likely correct for a strengthen question too. 
• Second, the correct answer can support the assumption by referring to a study, survey, or relevant evidence that makes the assumption more probable. Remember, you just need to make the argument more likely to be right, not certain.
• Weakening an argument follows a similar process but in reverse. Again, there are two possibilities.
  First, an answer that weakens the argument can directly challenge the assumption. Any choice saying the assumption is wrong weakens the argument.
  Second, just as new evidence can strengthen the argument, new evidence can weaken it. Any new info in an answer choice that makes the assumption less probable weakens the entire argument.

Understanding these common types of strengtheners and weakeners helps you quickly spot correct answers in strengthen/weaken questions, boosting your chances of achieving a higher GMAT score.