A map has a scale of 1 centimeter for 45 kilometers. If the real distance between 2 towns is 810 kilometers, how many centimeters long must a line segment be to represent the distance on the map?

In order to separate participants in a research study into groups, each will be given a card. The card will be one of 9 different colors, and each will contain one of 4 different shapes.
How many different cards are possible?

If n represents a negative number, which of the following expressions represents a positive number?

Two groups collected aluminum cans for a recycling drive. The first group had 40 members, and each collected 18 cans. The second group had half as many members, but each collected twice as many cans as any member of the first group had.
What was the total number of cans collected by the two groups?

Exhibit.

Which of the following graphs shows the number of pages yet to be duplicated in that print job as time goes by if the copying machine is not working?