When, on a particular shopping trip, a consumer purchases an item which he previously had no intention of purchasing, this sale is called an "impulse purchase." The objects of impulse purchases are occasionally essential items (i.e. items that satisfy basic subsistence needs), but much more frequently are luxury or non-essential items. Researchers have determined that, at the end of a shopping trip, a consumer is much more excited if she has bought a luxury item on an impulse purchase, than if she had made no impulse purchases. If the information above is true, and if the researchers` investigation was properly conducted, then which of the following must also be true?

In 1883, the Indonesian island Krakatoa, home to a massive volcano, seemingly disappeared overnight as an eruption rent the entire island apart, catapulting rock and debris into the atmosphere. For the next few years, as ash circled the entire globe, the average world temperature dropped by several degrees Fahrenheit. Therefore, an eruption of similar power in terms of the amount of debris ejected into the atmosphere will likely cause the average temperature around the world to drop by several degrees.Which of the following, if true, best challenges the main claim of the argument?

SafeZone mosquito repellant has been shown in laboratory settings to be effective for twelve hours against the female anopheles mosquito, the only mosquito that transmits malaria. SafeZone, however, is not effective against mosquitoes that do not transmit malaria. The only instance in which SafeZone does not repel the female anopheles mosquito is when this mosquito can detect any ruptured blood vessels, a state that inevitably results whenever any kind of mosquito bites a person. Therefore, assuming one does not have any ruptured blood vessels on their skin before applying SafeZone, that person will not be able to catch malaria for up to twelve hours.Which of the following, if true, would argue most against the use of SafeZone in areas in which malaria is endemic?

Nearly all employees of the factory who have completed their high school diploma have earned their factory safety certificate, having easily completed the eight week training course. The high school graduates who haven't earned the certificate are ones who have evening obligations that have prevented them from taking the course. Overall, though, most of the factory workers have not earned the certificate. If the statements above are true, which one of the following also must be true?

During the period in which there are no competitive races, two runners--Runners A and Runners B--take part in an experiment measuring their VO2 max, the volume of oxygen an athlete can use. During these sessions, the runners engaged in moderate aerobic activity, or a sustained heart rate between 146-154 beats per minute. At the end of the sessions, Runner A had a greater VO2 max than did Runner B. Therefore, once the two runners begin identical intensive training--sessions involving over 168 beats per minute-- for the race season, Runner A will continue to have the greater VO2 max, assuming that neither become injured and that both train with similar intensity.Which of the following is an assumption upon which the argument rests?

The number of United States citizens suffering from the flu increased significantly this year over last year. Since this increase did not occur among citizens of other countries, it is likely the result of a particular flu virus confined to the United States.

Which of the following, if true, would cast the most serious doubt on the explanation for the increase given above?

Operations at the Green Hills Gold Mine are continuously releasing mercury into the headwaters of the Apache River, and most fish in the Apache River now have mercury levels at or above the legal limit for human consumption. With the price of gold rising, forcing more and more mining at Green Hills, there seems no hope for food fishing along the Apache River.Which of the following plans, if feasible, would allow the state to assist the food fishing industries along the Apache?

When a married couple has frequent emotionally satisfying conversations, they tend in overwhelming percentages to remain married throughout their lives. Queen Melinda and Prince Jonathan, Duke of Westphalia, have been married for over sixty years, so clearly they must have emotionally satisfying conversations all the time. This argument is most vulnerable to what criticism?

A study of young children's ability to learn foreign languages found that those with parents who read them more than one book per week in their native language were 75% more proficient in the foreign languages that they learned than children whose parents read them one book per week or less. A secondary finding of the study was that children's ability to remember new vocabulary in a second language drops off sharply after the age of 6, when it becomes 75% more difficult to retain new words learned in the second language.Assuming the statements above are true, which of the following can be inferred from them?

Recidivism is the return to criminal behavior, and consequently a return to prison, of a former prisoner who has already served in incarceration for a criminal conviction. In the United States, most burglars and common thieves have a recidivist rate above 70%. Studies have shown that, when available, those incarcerated burglars and thieves who pursue post-secondary education while in prison have substantially lower recidivism rates. Therefore, the government should fund programs that assist incarcerated burglars and thieves in pursuing higher education, especially since ___________________________. Which of the following most logically completes the passage?

The CFO attributes our increased sales last year to the new markets in Eastern Europe. Nevertheless, a careful study of our revenue reveals a boom of sales in Southeast Asia, while the markets in Eastern Europe, after an early surge, settled at levels much lower than expected. After all, in Eastern Europe, our firm has fierce competition from both German and Russian exports, some of which offer exceptionally high quality at low cost. By contrast, no producers in this sector operate to the East of Turkey, and our firm is the only one in our sector with significant inroads into India, Thailand, Vietnam, and Taiwan. Current plans call for expansion into Eastern Europe, but the Southeast Asian markets hold much more promise. In the argument given, the two portions in boldface play which of the following roles?

In the last few years, a drastic spike in sea temperatures around Prudhoe Bay has caused the eggs of snow crabs to hatch earlier in the year than they had previously. As a result, baby snow crabs are more likely to be caught by deep sea fishing boats, since deep sea fishing boats are more numerous in Arctic waters during the fall season than they are during the winter season. Which of the following pieces of information is necessary to evaluate the argument?

Marketing chief: The aggressive sales campaign of Product J has made it the most popular product in the sector. Every individual move we made in that campaign was wildly successful, and sales of the product continuously rose. If we mount a similar style sales campaign with Product S, we are likely to vault this into popularity in its own sector, with a similarly robust sales trajectory. Consultant: The popularity of Product J preceded the sales campaign and was responsible for it. The consultant uses which of the following techniques in responding to the marketing chief?

The Bluetail Moonbeam, endemic to the streams and rivers of Asia, is regularly imported into the United States by companies wishing to breed it for food. An infectious virus has been threatening Bluetail Moonbeam stocks in the United States. Even before a Bluetail Moonbeam develops any symptoms, biologists can establish the presence of the infection by an inexpensive test for antibodies in the fish's blood. Yet, after the instance of infection, antibodies take about four weeks to appear in the fish's blood, and the test will find no results before then. Catching a live Bluetail Moonbeam and shipping it to the United States takes a little more than a week. Once the Bluetail Moonbeam is in captivity, shippers can eliminate all new sources of infection, but unfortunately, some Bluetail Moonbeams might be infected days or even hours before being caught. Thus, even running the antibody test on each Bluetail Moonbeam entering the country would still allow infected fish into the American stocks.Which of the following, if performed by the government, could logically be expected to overcome the problem with the plan to limit the spread of this virus in the Bluetail Moonbeam?

The Indonesian mimic octopus is able to camouflage itself from predators by blending into the background. Sometimes, though, even when a predator is nearby, the mimic octopus takes on a color pattern that is not present in the immediate environment. A marine biologist of cephalopods claims that this behavior is a sign of an octopus engaging in play, meaning that the behavior does not confer any specific advantage.Which of the following, if true, would most call in to doubt the marine biologist's claim?