People who have spent a lot of time in contact with animals often develop animal-induced allergies, a significant percentage of which are quite serious.  In a survey of current employees in major zoos, about 30 percent had animal-induced allergies.  However, a zoo employee who develops a serious animal-induced allergy is very likely to switch to some other occupation.

Which of the following hypotheses receives the strongest support from the information given?

People who have spent a lot of time in contact with animals often develop animal-induced allergies, some of them quite serious. In a survey of current employees in major zoos, about 30 percent had animal-induced allergies. Based on this sample, experts conclude that among members of the general population who have spent a similarly large amount of time in close contact with animals, the percentage with animal-induced allergies is not 30 percent but substantially more.

Which of the following, if true, provides the strongest grounds for the experts’ conclusion?

If 3 < x < 100, for how many values of x is the square of a prime number?

If , where the given expression extends till infinity, which of the following statements must be true ?

I. Two values are possible for z

II. 4 - z² = 2

III. z⁸ = 16

­Under laboratory conditions, fruit flies can learn to respond to odors that elicit no response from them in nature. Mutant fruit flies that cannot produce a certain enzyme are, however, incapable of such learning. These mutant flies respond to other odors just as ordinary fruit flies do. Thus it is unlikely that the enzyme's absence impairs the fruit flies' perception of odors, since presumably fruit flies would not have an enzyme that was needed only for the perception of odors that fruit flies do not respond to in nature. Given that many researchers believe that this enzyme is somehow involved in the process of forming memories, what the enzyme's absence probably impairs is the fruit flies' ability to learn.

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

Archaeologists using a remote-controlled submarine to excavate an ancient shipwreck deep in the Mediterranean have been able to recover several objects from the site of the wreck. By chemically dating the ship's timbers and examining other objects, such as coins, the archaeologists estimated that the ship was wrecked in the fifth century A.D. However, the submarine has also recovered from the site some large olive oil jars that cannot be from before the eighth century A.D.

Which of the following, if true, provides the strongest basis for explaining the apparent discrepancy in the dates cited?

Which of the following is equivalent to (10²)ⁿ⁺¹?

Which of the following is equivalent to the pair of inequalities x + 6 > 10 and x - 3 ≤ 5 ?

The integers 6, 9, 10, and 25 are each factors of the positive integer k. Which of the following integers must also be a factor of k?

I. 54

II. 60

III. 90

If x and y are integers and if (x−y)²+2∗y²=27, which of the following could be the value of x?