If n is a positive integer, what is the remainder when is divided by 10?

A school district is organized such that each of its D department heads has exactly T teachers reporting to her, and that each teacher has exactly S students. What is the ratio of students to department heads in this school district?

(1)

(2)

Advertising is one of the key revenue generators for the website drench.com. Based on a user’s preferences and profile, relevant advertisements are displayed to the user, and the company gets money every time the user clicks on an advertisement. Lately, however, applications that allow people to block advertisements have been gaining popularity among the users of drench.com. Therefore, to prevent any further decrease in the revenues, drench.com must ban such applications from running on its website.

Which of the following, if true, weakens the suggested plan of action in the above argument?

Which of the following most logically completes the passage below?

In Munghuria, the population of retired people receiving government pensions will increase by 5 percent over the next ten years, whereas the population of working people will remain relatively constant. Government pensions are paid for entirely by a special pension tax on workers' incomes .   It does not follow that Munghuria will have to increase tax rates on working people  , however, since __________.

Twenty percent of all energy consumed in the United States is consumed by home appliances. If appliances that are twice as energy-efficient as those currently available are produced, this figure will eventually be reduced to about ten percent.

The argument above requires which of the following assumptions?

The material traditionally used for make kettles in which water for teas is boiled is iron. When water is brought to a boil in these tea kettles, minute traces of iron dissolve in the water. These trace amounts of iron affect the taste of the tea. The use of tea kettles made of nontraditional materials that do not dissolve in water would therefore generally improve the taste of the tea.

Which of the following is an assumption on which the argument depends?

If the function g is such that g(x) = g(x– 1) – x + 2 and g(2) = 2, what is the value of g(5)?

Given a positive integer c, how many integers are greater than c and less than 2c?

Is the standard deviation of p,q, and r equal to the standard deviation of 4, 10, and 16?

1) q−p=6
2) r−p=12

The probability that event A occurs is 0.5 and the probability that event B occurs is 0.4, where A and B are independent events. What is the probability that neither A nor B occurs?