Practice Questions for Critical Reasoning | Verbal for GMAT PDF Download

Q1: The enormous distances between stars are not spaces entirely devoid of matter. The interstellar spaces are filled with "dust": very low-density matter. This minuscule amount of matter, spread over almost infinite distances, acts like a curtain obscuring the stars that lie behind. If it were not for this material, we would see no dark patches in the sky at night: the sky would be entirely covered with stars. 
The two parts in boldface play what roles in the argument above?
(a) The first is a suggestion that the author wishes to dispute. The second is a hypothesis that the author wishes to explain.
(b) The first is the main point the author wishes to make. The second is a hypothetical result of accepting that point.
(c) The first is a fact that the author thinks is important in explaining a certain phenomenon. The second is a result that the author would expect if that fact were not true.
(d) The first is a speculation that the author wishes to justify. The second is a consequence that would result if that speculation is not true.
(e) The first is an established fact that the author wishes to explain. The second is a consequence of accepting this fact.
Ans: (c)
The first part in bold is a statement of a fact. It is not the opinion of the author or speculation, and neither does the author dispute this fact, and so choices A and D can be eliminated. The second part is not a fact; it is a suggestion of what might happen if the first-mentioned fact were not true. Hence E and B can be eliminated. The correct answer is C.

Q2: In a recent study of responses to visual images, researchers found that women most frequently gave the rating "most attractive" to images of male faces that were more feminine in contour, and rated more masculine faces, on average, "less attractive." The researchers concluded that modern women prefer men who are less obviously masculine in their facial features.
The conclusion would be most severely weakened if which of the following were true?
(a) Facial features are not the criterion that most women use to decide whether a man is attractive.
(b) The visual images were computer-generated composites of photographs and not pictures of actual men.
(c) The rating scale was a ten-point scale with most attractive scoring 1-2 and least attractive scoring 8-10.
(d) Most popular male actors have the features that the study allocated to the more masculine category.
(e) The faces with the more masculine features were all significantly older than those with the feminine features.
Ans: (e)
The researchers are testing preference for one feature: the masculinity/femininity of the faces. However, if the faces have other differences, say race or size or age, then the subjects could be responding to that feature. In statement E, the correct answer, we have the possibility that the subjects are responding to age, a situation that is very damaging to the conclusion.

Q3:In a recent study of responses to visual images, researchers found that women most frequently gave the rating "most attractive" to images of male faces that were more feminine in contour, and rated more masculine faces, on average, "less attractive." The researchers concluded that modern women prefer men who are less obviously masculine in their facial features.
Which of the following is an assumption that the researchers apparently made in this study?
(a) The women who participated in the study were sufficiently representative of modern women in general.
(b) Male faces are, in general, attractive to women.
(c) Visual images are important to women.
(d) It is impossible to predict what features an ideal face would have.
(e) Women in previous ages would have preferred more masculine men.
Ans: (a)
The conclusion refers to "modern women" a fact that suggests the authors think their work applies to all modern women. Hence they do assume what is stated in A.

Q4: Photography is no longer an art form. Nowadays everyone has access to digital cameras that only need to be pointed at the subject in order to generate a perfect image.
The writer of the argument apparently assumes that
(a) the selection of the subject is not an important artistic factor in photography
(b) digital cameras will continue to improve in quality
(c) digital cameras can never go wrong
(d) photography with all other types of camera is an art form
(e) art is not perfect
Ans: (a)
Note that an assumption is like a premise in that if it is wrong the argument is invalid, and if it is right it supports the conclusion. If the statement in A is correct, it supports the idea that "point and shoot" is not art, but if it is wrong, and choosing what to point the camera at involves "art", then the argument is invalid. Hence, A is an assumption. The argument states that photography is not an art form because you only have to "point and shoot". This does not imply that the writer thinks digital cameras are perfect or will continue to improve, and so B and C are not assumptions. He does not assume that photography with ALL other cameras is art, and so D can be eliminated. He clearly does not imply that all art is not perfect.

Q5: Red is a color which has powerful effects on human beings as well as animals. A group of psychologists carried out an experiment which confirms the subconscious effects of this color on human behavior. They provided selected sports teams at school and college level with either red or blue shorts and recorded the outcome of the games. The teams wearing red won in a disproportionate number of matches. The psychologists suggested that either the teams wearing red subconsciously felt themselves more powerful, or that the non-red teams were subconsciously intimidated by the red color.
Which of the following, if true, would most weaken the psychologists' suggestion?
(a) Each team wore red in some matches and blue in others.
(b) The color blue has the subconscious effect of making human beings less competitive.
(c) The effect was only observed if all the team members wore white shirts.
(d) Red signifies danger in some cultures whereas it signifies happiness in others.
(e) In a subsequent study, teams with all-red outfits were more likely to report that they thought they would win no matter what color the opponents wore.
Ans: (b)
The conclusion concerns the supposed "powerful effects" of red color. However, if the observed results are due to the "power" of blue, the conclusion is not valid! The experimental design is flawed in that only two colors are used and the so-called positive effect of red cannot be distinguished from a possible negative effect of blue.

Q6: The number of people diagnosed with dengue fever (which is contracted from the bite of an infected mosquito) in North India this year is twice the number diagnosed last year. The authorities have concluded that measures to control the mosquito population have failed in this region.
All of the following, if true, would cast doubt on the authorities' conclusion except
(a) more cases are now reported because of increases in administrative efficiency
(b) a very high proportion of the cases were in people who had recently returned from neighboring countries
(c) an effective diagnostic test was introduced about nine months ago
(d) the disease is prevalent only in some industrialized areas which have shown a dramatic increase in population due to migration
(e) the incidence (number of cases per thousand) of malaria, also contracted from mosquito bites, has increased
Ans: (e)
The authorities conclude that measures to control mosquitoes have failed. We need to find something that does not contradict that conclusion. But first we need to find the four items that do cast doubt on that conclusion. If the disease is contracted in another country, or if numbers reported are increasing because of better tests or reporting methods, or simply because the human population is increasing, then we cannot conclude that control measures have failed. However, if the incidence of another mosquito-borne disease is increasing, it is more likely to indicate that mosquitoes are not controlled.

Q7: Sue: Commercial flights currently contribute more carbon dioxide to the atmosphere in one year than does the whole of Africa. If we want to reduce global warming we need to restrict the number of flights we take.
Dave: Did you know that by taking one inter-continental flight you cause more pollution than you would in twelve months of car travel?
Dave’s response to Sue’s comment serves to
(a) reinforce Sue’s contention that flights are a major contributor to increased carbon dioxide levels
(b) add more weight to her contention that we should reduce the number of flights we take
(c) mitigate the force of her argument by suggesting that there is an alternative approach
(d) suggest an alternative that will reduce the effect of pollution
(e) question whether she really understands the severity of global warming
Ans: (b)
Since Dave's comments don't challenge what Sue says, we can eliminate answers E and C (mitigate = lessen). His comments reinforce what she says and so A sounds tempting but is wrong since Dave talks about pollution in general and doesn't mention carbon dioxide. Of the remaining choices, B is best since Dave does give information that suggests, like Sue, that we should take fewer flights. (D is incorrect mainly because Dave is not talking about the 'effect' of pollution. Note how careful you have to be that all the words in an answer are exactly right.

Q8: It is not unusual to see the ball fall into a black slot on a roulette wheel four times in a row. But for it to fall five or six times in a row into the same color is very unusual. Therefore you can win money by waiting for a run of five of the same color and then betting against that color.
If the roulette wheel in question is a fair wheel, which of the following observations or facts, if it were true, would best reveal a fallacy in the logic?
(a) If there were a reliable way to win at roulette, it would be well-known by now.
(b) It is hard for a player to keep track of what went before for the time required.
(c) The probability of getting a particular color decreases with the number of times the color has appeared.
(d) The probability of getting a particular color is always the same no matter what has gone before.
(e) A person who makes money this way once or twice, will carry on to lose that money after a few more times.
Ans: (d)
In critical reasoning questions many of the answer choices can be factually correct or reasonable sounding, and so eliminating without understanding the question is not possible. Your job is to find the best answer to the specific question, so read carefully. A fallacy in the logic is an error in the thinking behind the proposal. The person concludes that if you wait for a run of five of the same color and then bet against the color, you WILL win. Now the logic behind that suggests that the probability of getting that same color again is low. But just as tossing a fair coin always gives an even chance of a head or tail no matter what has gone before, the probability of getting a color is always the same no matter what has gone before.

Q9: On the basis of the Big Bang theory scientists predicted levels of Helium-3 in the universe that are ten times greater than the levels actually observed. According to the original model, Helium-3 is produced when low-mass stars burn up hydrogen and become ‘red giants’, as well as being produced in the Big Bang itself. Researchers have now produced a new model in which the Helium-3 produced by a red giant is pushed to the star’s interior and burnt up. Hence the Big Bang theory is no longer undermined by Helium-3 data.
The two portions in bold-face are related to each other in which of the following ways?
(a) The first highlights an observation that tends to undermine a particular theory. The second is that theory.
(b) The first is a fact that undermines a theory. The second is context for accepting that theory.
(c) The first points to an inconsistency in a particular model; the second is the author’s main conclusion.
(d) The first is a challenge to a classic theory; the second resolves that challenge.
(e) The first is a position that the author does not accept; the second is the author’s position.
Ans: (c)
Study each sentence carefully and decide whether it is a fact, and assumption or a conclusion. The first part in bold is a factual statement of a certain prediction. The second part in bold is a statement of the author's view or position on the situation. A view or a position is another way of thinking about a conclusion. So, start with looking for answers that say the second is a conclusion. Now we can have a closer look at C and E. Since the first part is a factual statement, we cannot say that the author does not accept it, and we are left with C. The word 'inconsistency' is fine as the predicted amounts do not match with the observations.

Q10: The committee on sexual discrimination in the workplace has highlighted Supremo Company as a chief offender. Of the twenty senior executives in the firm, only one is a woman. And of the forty junior executives, only five are female. Supremo could best defend itself against the charges by showing that
(a) male and female executives at the same level have the same qualifications
(b) they pay the same salary to senior men and senior women
(c) ten times more men than women apply for jobs with the company
(d) the work pressures and long hours make jobs with the company unattractive to married women
(e) all job applicants who were rejected had fewer qualifications than those accepted
Ans: (e)
To defend itself against a charge of discrimination the company will have to show its selections were made on the basis of merit not sex. The best way to do that is to show that none of the women who were rejected had better qualifications than the men who were appointed. Answer E implies just that but without specifying the sex of the rejected applicants.