GMAT

Numbers
All numbers used are real numbers.

Figures
A figure accompanying a data sufficiency question will conform to the information given in the question but will not necessarily conform to the additional information given in statements (1) and (2).
Lines shown as straight can be assumed to be straight and lines that appear jagged can also be assumed to be straight.
You may assume that the positions of points, angles, regions, etc. exist in the order shown and that angle measures are greater than zero.
All figures lie in a plane unless otherwise indicated.

Q.

When Y is divided by 2, is the remainder 1?
1. (-1) ^(Y+2) = -1
2. Y is prime.

The Erythrovirus412, which affects farmed Atlantic salmon, infects human beings by adhering to red blood cells. The virus elevates the body’s white blood cell count, indicating that the body is fighting an infection. Surprisingly, when a group of recently-infected people were tested, the proportion of white blood cells compared to red blood cells in their bodies was similar to that of an uninfected person.

Which of the following, if true, most helps to explain the surprising finding?

Analyst 1: Many parents take their children along when they go for shopping for toys because they want to know whether the children will really enjoy playing with a toy before buying it for them. But in many cases, children ask for toys that are either out of their parents’ budgets or are somewhat unsafe for the children. Either way, it is not a good idea to take children along when shopping for toys.

Analyst 2: But since parents have the ultimate authority to decide whether to purchase a particular toy, your consideration is not valid.

Which of the following, if true, most helps to strengthen the conclusion drawn by analyst 1?

Choice overload is a term used to describe the effects of having too many options to choose from while making a decision. Under such conditions, people usually feel paralyzed and as a result are unable to make decisions for themselves. However, various studies have shown that when making decisions for others, people face what is called “reverse-choice overload”. In other words, people are enthused and more decisive while making decisions from a wide variety of available options. Clearly, people are less careful while making decisions for others and hence are not overwhelmed with the stress to make the choice. 

Which of the following, if true, provides the most support for the argument?

Customers are aware that most of the faults that arise in their mobile phones are due to the excessive exposure of these phones to moisture or water. Accordingly, engineers at Talkit Inc. have developed a water-resistant phone that can stay underwater for at least 30 minutes without any resultant damage to either its hardware or software. However, since the manufacturing cost of the phone is anywhere between 25-30% more than that of an ordinary phone, trade analysts have predicted that the phone will be very expensive and as such not be able to find enough customers. 

Which of the following, if true, argues in favor of the assertion that the analysts’ prediction is premature?

Parent: It is as misleading to conclude that decreasing attendance in after-school extra classes shows that our children’s academic requirements are finally being fully met in regularly-scheduled classes as it is to reason that teachers do not get negative ratings from students because students respect and admire teachers. The real cause behind the decreasing attendance is that the same teachers who teach the regular classes teach the after-school ones, and students don’t like the methodology used by these teachers in the first place. 

The parent’s statements, if true, best support which of the following conclusions?

Eating fish and other foods rich in omega-3 fatty acids could help people maintain healthy brains as they age as well as protect their hearts, new research suggests. Per this research, participants with low levels of omega-3 fatty acids in their blood had slightly smaller brains and scored lower on memory and cognitive tests than people with higher blood levels of omega-3s.

The researchers then looked at and ranked the level of omega-3 fatty acids in the participants' blood. People who scored in the bottom 25% in omega-3 fatty acid levels were compared with the rest of the study participants. Researchers found that those who had the lowest level of omega-3 fatty acid levels in their blood had lower brain gray matter volume compared with those with higher levels.

Gray matter volume is crucial to brain health. When it remains higher, brain health is being maintained. Decrease in gray matter volume indicates that brain cells are shrinking. The findings showed that consumption of baked or broiled fish on a weekly basis was positively associated with retention of gray matter volume in several areas of the brain. In fact the greater hippocampal, posterior cingulate, and orbital frontal cortex volumes obtained by optimal fish consumption led to reduced risk of contracting MCI or Alzheimer’s by almost five-fold.

The most recent U.S. dietary guidelines—released last year—recommend at least two servings of seafood a week. Some doctors and diet experts recommend that patients consume fish three times a week or take fish-oil supplements so they get enough omega-3 fatty acids to obtain health benefits.

The experiment discussed in paragraph 2 suggests

A man starts rowing from Point A in the direction of the water flow at a constant speed of 10 kilometers per hour. After rowing for 10 kilometers, he remembers that he forgot an important object at Point A and turns back to get it. After getting the object, he starts moving again in the direction of water flow, but due to an onset of exhaustion, he now rows at a constant speed of 8 kilometers per hour. After rowing for 26 kilometers, he reaches Point D, where he rests for 1 hour, and then resumes his journey in the same direction, rowing at a constant speed of 9 kilometers per hour, till he reaches Point B, which is 14 kilometers downstream from Point D. If the speed of water flow is 5 kilometers per hour, what is the average speed of the man for the entire journey?

The role of nurturing in determining one’s behavioral traits has been hotly contested. Historically, geneticists believed that behavioral traits are inherited. After all, many properties of the brain are genetically organized and don't depend on information coming in from the senses. Since active genes are essentially inherited, most traditional geneticists believe that nurturing environment plays little role in shaping one’s behavioral traits.

However, a new line of research indicated that methyl groups can activate dormant genes, bringing about a slew of changes much later in a person’s life. The methyl group works like a placeholder in a cookbook, attaching to the DNA within each cell to select only those recipes - er, genes - necessary for that particular cell’s proteins, telling the DNA what kind of cells to form.  The first such observation was in which methyl groups activated by causes ranging from exposure to certain chemicals to changes in diet set off a cascade of cellular changes resulting in cancer. Because methyl groups are attached to the genes, residing beside but separate from the double-helix DNA code, their study is dubbed epigenetics - “epi” referring to Greek for outer or above. 

Behavioral geneticists, encouraged by this discovery proved that traumatic experiences such as child neglect, drug abuse, or other severe stresses also set off epigenetic changes to the DNA inside the neurons of a person’s brain, permanently altering behavior.  Similarly, through multivariate analysis, they proved that identical twins, in scenarios where one twin has gone through a life altering event, can have vastly different reaction to a stressful situation.

The primary purpose of the passage is to

In a poll released September 16, Gallup found that nearly twice as many Americans believe that there is "too much government regulation of business and industry" than those who believe there is "too little" (45% to 24%).

In an attempt to improve the economic and social welfare of the people, the government has recently announced a scheme under which it will provide certain staple foods at 30% discount to the authorized dealers. The reduction in the prices of these foods will significantly improve the economic conditions of the people from low income groups.

Which of the following would be most useful to establish in evaluating the argument?

Eating fish and other foods rich in omega-3 fatty acids could help people maintain healthy brains as they age as well as protect their hearts, new research suggests. Per this research, participants with low levels of omega-3 fatty acids in their blood had slightly smaller brains and scored lower on memory and cognitive tests than people with higher blood levels of omega-3s.

The researchers then looked at and ranked the level of omega-3 fatty acids in the participants' blood. People who scored in the bottom 25% in omega-3 fatty acid levels were compared with the rest of the study participants. Researchers found that those who had the lowest level of omega-3 fatty acid levels in their blood had lower brain gray matter volume compared with those with higher levels.

Gray matter volume is crucial to brain health. When it remains higher, brain health is being maintained. Decrease in gray matter volume indicates that brain cells are shrinking. The findings showed that consumption of baked or broiled fish on a weekly basis was positively associated with retention of gray matter volume in several areas of the brain. In fact the greater hippocampal, posterior cingulate, and orbital frontal cortex volumes obtained by optimal fish consumption led to reduced risk of contracting MCI or Alzheimer’s by almost five-fold.

The most recent U.S. dietary guidelines—released last year—recommend at least two servings of seafood a week. Some doctors and diet experts recommend that patients consume fish three times a week or take fish-oil supplements so they get enough omega-3 fatty acids to obtain health benefits.

According to the passage, people who eat foods rich in Omega 3 acids experience which of the following benefits

Proverbial wisdom states that “birds of a feather flock together.”  Studies have shown that people of similar geographical and educational backgrounds and functional experience are extremely likely to found companies together.  Not considering spousal teams in the dataset, it has been found that a founding team is five times more likely to be all-male or all-female team.  Also, it is more likely to find founding teams that are remarkably homogenous with regard to skills and functional backgrounds.  

Homogeneity has important benefits. For the founder struggling to meet the challenges of a growing startup, selecting cofounders from among the people with whom he or she probably has important things in common is often the quickest and easiest solution. Not only does it generally take less time to find such people, but it also generally takes less time to develop effective working relationships with such similar people.  When founders share a background, they share a common language that facilitates communication, ensuring that the team begins the work relationship with a mutual understanding and hence can skip over part of the learning curve that would absorb the energies of people with very different backgrounds.  Increasing homogeneity may therefore be a particularly alluring- and, in some ways, a particularly sensible - approach for novice founders heading into unfamiliar territory.  Certainly, studies have found that the greater the heterogeneity among executive team members, the greater the risk of interpersonal conflict and the lower the group-level integration.  Even though it is very appealing to opt for the “comfortable” and “easy” decision to found with similar cofounders, by doing so founders may be causing long-term problems.  Teams with a wide range of pertinent functional skills may be able to build more valuable and enduring startups.  Conversely, homogenous teams tend to have overlapping human capital, making it more likely that the team will have redundant strengths and be missing critical skills.

From the passage, which of the following cannot be inferred as a benefit of homogenous teams?

During a trip, Charles covered the first part of a certain distance at an average speed of 30 miles per hour and the remaining part at an average speed of 50 miles per hour. If the ratio of time taken to cover the first part and remaining part is 2: 3, then what is the total distance that Charles travelled?

(1) It took a total of 5 hours to complete the entire distance.

(2) 2/7^th of the entire distance was covered during the first part

Fast food chains constantly face the problem of low employee retention, to counter which the companies offer high salaries. The companies have come up with the solution of hiring retired people who have a very low attrition rate. However, their time taken to service an order is more and they require going through long training programs at regular intervals. Thus, for most fast food chains the gain in employee retention does not compensate for the increase in time taken to serve each customer. Nevertheless, since the customers continue to be more appreciative when served by retired people, their employment is likely to become an industry-wide feature.

In the argument above, the two portions in boldface play which of the following roles?