Are you preparing for the GMAT? Struggling with the GMAT Critical Reasoning questions? Don’t worry! We will help you understand these Critical Reasoning questions and the types of reasonings you need to be aware of to solve these questions. We will explain to you the two kinds of reasoning —Critical Reasoning: deductive and inductive reasoning. But first let’s give you a brief overview of this question type.
The GMAT Critical Reasoning tests your ability to evaluate arguments by examining the logic the argument is based on. The questions in this section are based on a very short passage, less than 100 words. These short passages are based on general topics and you do not need any external knowledge of the topic to answer these questions. However, you need to know how to logically analyse and evaluate the arguments in the passage to answer the questions.
Now,let’s look at what deductive and inductive reasoning is.
Types of Reasoning: Deductive Reasoning and Inductive Reasoning
Every argument consists of an assumption and a conclusion, but not every argument concludes in the same manner. To be able to distinguish how an argument concludes, you need to be familiar with the two kinds of reasoning used in the GMAT — Deductive and Inductive Reasoning.
As the term “deductive” suggests, this type of reasoning requires you to deduce a conclusion from the given assumption. For example, “Bachelors is a term used for unmarried men, Joe is unmarried”. From this information, we deduce that since Joe is unmarried, he is a bachelor. We concluded from the given information in the above statement. Hence, deductive reasoning draws a specific conclusion from the general facts or information available in the argument.
Unlike deductive reasoning, inductive reasoning refers to when you draw a general conclusion from specific facts or assumptions given in an argument. For example, “ Radha pulled out a coin from her bag and it turned out to be a rupee”. From this information, we can assume the bag contains only one rupee coin or we can also assume that one of the coins in the bag is a one-rupee coin. While we have a specific fact from the argument, information on what the bag itself contains is missing. Hence, answering an inductive reasoning question will require you to use probability and give it your best guess as complete information will not be provided to you.
Differences between Deductive and Inductive Reasoning
The differences between deductive and inductive reasoning are as follows:
|Deductive Reasoning||Inductive Reasoning|
|With deductive reasoning, you arrive at a specific conclusion based on general facts and assumptions made in the argument.||With inductive reasoning, you arrive at a general conclusion based on specific instances in an argument.|
|Deductive Reasoning deals with establishing a conclusion as the absolute truth.||Inductive Reasoning deals with strengthening the probability of a conclusion.|
|The conclusion of a deduced argument is certain as the facts stated in the argument.||The conclusion in an inductive argument is probable and we can only weaken or strengthen arguments.|
Now that you know how to distinguish between deductive reasoning and inductive reasoning. Let us have a look at a few sample questions to help you understand better.
Sample Questions for Inductive Reasoning
As mentioned above, the conclusion to an inductive reasoning question is probable. Hence, you can only strengthen the probability of the conclusion. In the GMAT Critical Reasoning section, you will have questions based on inductive reasoning. These questions will require you to pick out statements that would either strengthen or weaken a specific argument.
Here is an example of the ‘strengthen an argument’ question:
A nationwide study of children’s eating habits found that children aged 7 – 13 who consumed more than 200 grams of sugar through food and beverage performed worse in school than children of the same age who consumed fewer than 200 grams of sugar as part of their weekly diet. Therefore, parents of children aged 7- 13 should prohibit their children from consuming over 200 grams of sugar per week, which includes the sugar in their food and beverages.
Which of the following, if true, would best strengthen the argument above?
A: Children who consume excess sugar are more likely than others to maintain that habit as an adult.
B: Children who consume more than 200 grams of sugar each week also scored lower in physical fitness tests compared to children who consumed fewer than 200 grams of sugar each week.
C: The study gave appropriate weight to children of backgrounds representative of children nationwide.
D: A separate study, by a renowned graduate school, found that when parents prohibited their children from consuming more than 50 grams of sugar each week, the children’s reading scores increased rapidly and significantly and stayed high indefinitely.
E: The carbonated beverages that children, aged 7 – 13 drink, are most likely to have large quantities of sugar, much more than the recommended daily amounts.
Correct answer: C
Explanation: The argument states that children in the study who consumed more than 200 grams of sugar each week were more likely to perform poorly in school. Hence, they concluded that sugar consumption must be limited to under 200 grams each week for children of the age of Answer3. The fact that this is based on a study, brings suspicion on the representativeness of the sample used. We do not know whether the study is properly accounted for by the different demographics and backgrounds of the children in the country.
Option A depicts that they maintain the habit as adults have no bearing on the argument. Option B depicts that they did poorly on physical fitness, while a sign of detrimental effect, still doesn’t help bridge the link between the results of the sample and performance in school for all children. Option C correctly addresses the gap in logic and helps indicate that the study represents the general population. If the study was focused on low-income groups only, then the results might not be reliable as these groups might not consume high amounts of sugar and would yet perform badly in school. The reason for both could be socio-economic factors rather than sugar being the cause for bad school performance. Option D indicates that less than 50 grams of sugar are out of context. This again could be a result of other factors such as social or affluence. Finally, option E just indicates that carbonated beverages have high levels of sugar and does not address the gap in the argument.
Here is an example of the ‘weaken the argument’ question:
A cross-sectional study of 8000 people conducted in central Asia found that participants who regularly consume high doses of vitamin K supplements had a significantly lower than average risk of haemophilia, a severe blood clotting disorder in which the body fails to produce enough platelets to effectively clot bleeding. This unambiguously shows that people who take vitamin K supplements tend to live healthier than average.
Which one of the following, if true, would most weaken the argument in the newspaper article?
A: The reduction in risk of haemophilia due to the consumption of vitamin K is no greater than the reduction due to certain other dietary changes.
B: Taking both vitamin K supplements and vitamin E supplements lowers one’s risk of haemophilia far more than does taking either one alone.
C: High doses of vitamin K supplements tend to reduce one’s resistance to certain common infectious diseases.
D: Taking vitamin K supplements has been found to lower one’s risk of developing cancer.
E: Vitamin K taken in the form of supplements has a different effect on the body than does vitamin K taken in food.
Correct Answer: C
Explanation: The argument concludes that people who take vitamin K supplements tend to live healthier lives. This is based on a study on 8000 people and the fact that taking large doses of vitamin K helped reduce the risk of haemophilia. The gap here is that lowering the risk of haemophilia is not the same as having a healthier life. There might be other ill effects associated with taking vitamin K supplements that might make it less likely to lead to a healthier life.
Option A indicates that ‘other dietary changes’ is out of scope, we aren’t bothered about haemophilia anymore either, we need to weaken the link between a lower rate of haemophilia and being more healthy. Option B indicates that taking vitamin E as well as K supplement is more effective, does not relate to ‘healthy’ or the efficacy of vitamin K leading to a healthier life. Option C correctly states the side-effect of taking vitamin K supplements. This could lead to a less healthy life as opposed to not taking this supplement at all. Option D indicates a benefit and not a demerit of the supplement. Hence, you should eliminate this answer choice. Option E indicates that Vitamin K has a ‘different’ effect on your body. Different doesn’t mean worse, so you should eliminate this choice as well.
The GMAT also tests you on deductive reasoning, the questions based on deductive reasoning require you to draw the most appropriate inference from the facts provided to you.
Here is an example of an inference based question:
The total market value of real estate in Miami has decreased over the past four years. This decline has meant that the overall figure on which the city’s property tax is based—the assessed value of that real estate—has also declined. Moreover, the percentage of assessed value that was paid as property taxes to the city did not change during this period.
The information above most strongly supports which of the following?
- Money collected from property taxes provided most of Miami’s revenue during the past four years.
- The percentage of Miami’s overall revenue that was collected from property taxes did not change over the past four years.
- Miami officials had proposed raising property tax rates during the past four years but never did so because of strong opposition from property owners.
- The total amount of revenue that Miami has collected from property taxes has declined over the past four years.
- During the past four years, Miami officials also did not increase tax rates on other sources of revenue such as retail sales or business profits.
Correct Answer: D
Explanation: Since we have to draw an inference, we need to directly examine the options and find one that is 100% true. With option A we don’t have information to support the money collected. Hence it has to be eliminated. Option B does not indicate any information to support the raise. This, too, has to be eliminated. Hence eliminated. Option C has no information to support the raise. So, it has to be eliminated. Finally, option E indicates no information about other sources of revenue and this option has to be eliminated. Hence, option D is the correct answer.
We hope now you understood the GMAT Critical Reasoning: deductive and inductive reasoning question types. All you need to do now is practice and prepare well.
All the best!