Although the earliest records we have of Arabic sources using the numeral zero date back to 773 C.E., the fact that the Arabic civilization had been performing advanced mathematical operations for a century before that indicates that they understood the concept of numerical zero long before they ever put it in writing. After all, Indians and Babylonians had both developed the concept independently before then, and the Arabic people could reasonably be expected to have acquired similar concepts. And although there is a dearth of writing indicating the exchange, by the 6th century C.E. Arabs had been in close contact with Indian civilization for a prolonged period.

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

Political correspondent: The theory of Mutually Assured Destruction (MAD) dictates that any country threatened by another country armed with nuclear weapons should then arm itself with nuclear weapons as a deterrent to that other country’s nuclear attack. If every country were to adopt this policy, no country would be without nuclear arms.

The political correspondent’s argument relies on which of the following assumptions?

Between 2000 and 2010, the number of bass in the Mississippi River and its tributaries experienced a catastrophic decline. There is little evidence that pollution or disease was the cause, so it is likely that there was an increase in the number of bass killed by other means. Typically, recreational fishermen in the region prefer to pursue several varieties of river trout, but a state law passed in 2001 banned the catching of trout in the area. Thus, it is likely that recreational fishing was the immediate cause of the decline of the bass population.

Which of the following, if true, most strengthens the argument?

Larger national education budgets do not produce higher scores on international standardized tests. If they did, countries with the highest education budgets would likewise have the highest standardized test scores. In fact, when education budget figures are analyzed in such a way as to make them readily comparable between countries, any correlation between the two factors is negligible.

If the statements above are all true, which of the following can properly be inferred on the basis of them?

A proposed rule requires the installation of guardrails on all traffic bridges in the state of Willericka. However, an engineer argued that because traffic accidents on bridges account for only 2 percent of all traffic accidents in Willericka, guardrails would do little to reduce the number of traffic injuries.

Which of the following, if true, would most seriously weaken the engineer’s argument?

Electronics can rust if their surface metals contain iron and are exposed to the atmosphere. Polyethylene, the chemical used in most plastic products, can protect metals from the atmosphere. Iron is non-reactive with polyethylene and polyethylene is readily available to electronics manufacturers. When the surfaces of electronics were treated with polyethylene coatings and exposed to the atmosphere, none of them became rusted during the period they were observed.

In deciding whether polyethylene coating would be useful in producing rust-free electronics for sale to consumers, it would be most helpful to determine which of the following?

Laws making it more difficult to discharge debt can reduce the rates of bankruptcy. However, because some debtors have no recourse but to file for bankruptcy, those laws should only apply in circumstances where discharging debt is unnecessary. In fact, the only individuals who should be subject to those laws are those for whom declaring bankruptcy would be a form of fraud.

Which of the following conclusions could be most properly drawn from the information given above?

In the context of the passage, the phrase “poor outcomes” () most closely corresponds to which of the following phrases?

The passage mentions each of the following as desirable legislative action EXCEPT

The committee recommends that principals should devise intervention plans, their staffs should be organized into collaborative teams, and demand accountability.

The voice box has been a subject of considerable investigation among researchers studying the origins of language because they have believed for a long time that if humans did not have a low larynx, the use of vocal language was always impossible.

Kazuo Ishiguro’s literary roots in England, where he has lived since the age of five, are obvious in novels that range in style from his Booker-Prize-winning portrayal of a devoted butler in The Remains of the Day and his fantasy depiction of Britain in the days after King Arthur, The Buried Giant.

Many psychologists believe that while some poor choices by parents can certainly damage their children’s social development, no family can truly be expected to check or limit all of the complicated social media that shape a child’s awareness of the world.

The Charles Hudson School has for years pursued a consistent strategy aimed at tutoring its weakest students and strengthening the effectiveness of its student support services.

The chief minister of Herod the Great wrote the first reliable description of the assassination of Julius Caesar in a biography of the emperor Augustus.

A lawyer charging a judge with misconduct may find it challenging to establish her argument if there is a lack of some other lawyer to corroborate about inappropriate legal proceedings.

In comparable restaurants with similar diner profiles, the total cost of a steak dinner has always been greater in Fairview than in Centerville, two towns of about equal populations. However, consumer studies indicate that steakhouses in Fairview process more meal transactions than steakhouses in Centerville. Therefore it is obvious that restaurant owners in Fairview are more successful than those in Centerville.

In evaluating the argument, it would be most useful to compare

Individuals who heavily use social media tend to score more poorly on tests administered by psychologists to measure happiness than those who do not. It has been found that experiencing “status envy,” a state afflicting those who see themselves as being worse off than others—especially common among those who make use of social media—depletes the brain of chemicals responsible for feelings of joy and contentment. Obviously, there is a causal relationship: Extensive use of social media must be making people unhappy.

Which of the following, if true, most seriously undermines the force of the evidence given as support for the hypothesis that social media promotes unhappiness?

Day Sales Outstanding (DSO) is a measure of how many days a company is left waiting on payment for services rendered. The construction industry faces especially high rates of late payment, with an average DSO of about 80 days. Such late payments make it extremely difficult for construction companies to manage their cash flow.

Which of the following plans, if feasible, would best allow a company to address the problem of late payments?

High school principal: Many students will complete and hand in assigned homework, even if doing so isn’t compulsory. Some will do more than assigned because they recognize it is an effective means of studying. Our school could therefore increase the amount of homework completed by students if we make doing so optional and present it as an alternative method of studying.

Teacher: This plan is likely to fail. A significant number of students will decide that all homework is optional and use the opportunity to spend less time overall on academics.

Which of the following, if true, would best support the principal’s plan, in light of the teacher’s concern?