LSAT Section 1 Logical Reasoning

LSAT Section 1 Logical Reasoning practice questions, page 10 of 16, with answer review and explanations.

Question 46

It is well known that many species adapt to their environment, but it is usually assumed that only the most highly evolved species alter their environment in ways that aid their own survival. However, this characteristic is actually quite common. Certain species of plankton, for example, generate a gas that is converted in the atmosphere into particles of sulfate. These particles cause water vapor to condense, thus forming clouds. Indeed, the formation of clouds over the ocean largely depends on the presence of these particles. More cloud cover means more sunlight is reflected, and so the Earth absorbs less heat. Thus plankton cause the surface of the Earth to be cooler and this benefits the plankton. Which one of the following accurately describes the argumentative strategy employed?

  1. A general principle is used to justify a claim made about a particular case to which that principle has been shown to apply.
  2. An explanation of how a controversial phenomenon could have come about is given in order to support the claim that this phenomenon did in fact come about.
  3. A generalization about the conditions under which a certain process can occur is advanced on the basis of an examination of certain cases in which that process did occur.
  4. A counterexample to a position being challenged is presented in order to show that this position is incorrect.
  5. A detailed example is used to illustrate the advantage of one strategy over another.

Question 47

The top priority of the school administration should be student attendance. No matter how good the teachers, texts, and facilities are, none of these does any good if few students come to school. The pattern of reasoning in the argument above is LEAST similar to that in which one of the following?

  1. The top priority of a salesperson should be not to alienate customers. Honesty and a good knowledge of the product line are useful to a salesperson only if the customer feels at ease.
  2. The top priority of a person lost in the wilderness should be food-gathering. Knowing how to find one's way back or how to build a comfortable shelter does one no good if one does not have enough food to survive.
  3. The top priority of a detective should be to gather physical evidence. High-tech crime lab equipment and the most sophisticated criminological analysis are of no use if crucial clues are not gathered.
  4. The top priority of a library should be to maintain its collection of books. A knowledgeable staff and beautiful facilities are of no value if there is an inadequate supply of books to lend.
  5. The top priority of a criminal defense lawyer should be to ensure that innocent clients are found not guilty. Such clients can justly be released from jail and resume their normal lives if they are found not guilty.

Question 48

Prosecutor: Dr. Yuge has testified that, had the robbery occurred after 1:50 a.m., then, the moon having set at 1:45 A.M., it would have been too dark for Klein to recognize the perpetrator. But Yuge acknowledged that the moon was full enough to provide considerable light before it set. And we have conclusively shown that the robbery occurred between 1:15 and 1:30 A.M. So there was enough light for Klein to make a reliable identification. The prosecutor's reasoning is most vulnerable to criticism because it overlooks which one of the following possibilities?

  1. Klein may be mistaken about the time of the robbery and so it may have taken place after the moon had set.
  2. The perpetrator may closely resemble someone who was not involved in the robbery.
  3. Klein may have been too upset to make a reliable identification even in good light.
  4. Without having been there, Dr. Yuge has no way of knowing whether the light was sufficient.
  5. During the robbery the moon's light may have been interfered with by conditions such as cloud cover.

Question 49

Ordinary mountain sickness, a common condition among mountain climbers, and one from which most people can recover, is caused by the characteristic shortage of oxygen in the atmosphere at high altitudes. Cerebral edema, a rarer disruption of blood circulation in the brain that quickly becomes life-threatening if not correctly treated from its onset, can also be caused by a shortage of oxygen. Since the symptoms of cerebral edema resemble those of ordinary mountain sickness, cerebral edema is especially dangerous at high altitudes. Which one of the following is an assumption on which the argument depends?

  1. The treatment for ordinary mountain sickness differs from the treatment for cerebral edema.
  2. Cerebral edema can cause those who suffer from it to slip into a coma within a few hours.
  3. Unlike cerebral edema, ordinary mountain sickness involves no disruption of blood circulation in the brain.
  4. Shortage of oxygen at extremely high altitudes is likely to affect thinking processes and cause errors of judgment.
  5. Most people who suffer from ordinary mountain sickness recover without any special treatment.

Question 50

We can learn about the living conditions of a vanished culture by examining its language. Thus, it is likely that the people who spoke Proto-Indo-European, the language from which all Indo-European languages descended, lived in a cold climate, isolated from ocean or sea, because Proto-Indo-European lacks a word for "sea," yet contains words for "winter," "snow," and "wolf." Which one of the following, if true, most seriously weakens the argument?

  1. A word meaning "fish" was used by the people who spoke Proto-Indo-European
  2. Some languages lack words for prominent elements of the environments of their speakers.
  3. There are no known languages today that lack a word for "sea."
  4. Proto-Indo-European possesses words for "heat."
  5. The people who spoke Proto-Indo-European were nomadic