From 2005 through 2014 , the number music CDs sold in the United States declined each year by approximately 15% of the number sold the preceding year. In 2005 , approximately 600 million CDs were sold in the United States. Of the following, which best models C, the number of millions of CDs sold in the United States, t years after 2005 ?

The graph of the equation ax + ky = 6 is a line in the xy-plane, where a and k are constants. If the line contains the points (-2 , -6) and (0 , -3), what is the value of k ?

The world’s population has grown at an average rate of 1.9 percent per year since 1945. There were approximately 4 billion people in the world in 1975. Which of the following functions represents the world’s population P, in billions of people, t years since 1975 ? (1 billion = 1,000,000,000)

We know the world's population one year after 1975 can be written as food into 1.01, nine to twelve years after 1975 can be written as '4' into 1.0 192, and so on. Similarly, suppose we continue to calculate three years after 1975. In that case, the world population will be 4.1.0 1923, and finally, we can conclude that the world population two years after 1975, as determined by the function P of t, will be equal to 4 into 1.0 19 t, and we can see that option one is the correct answer.

f(x) = -500x² + 25,000x
The revenue f(x), in dollars, that a company receives from sales of a product is given by the function f above, where x is the unit price, in dollars, of the product. The graph of y = f(x) in the xy-plane intersects the x-axis at 0 and a. What does a represent?

Refer to the following information.
If the 180 food calories in a granola bar come entirely from p grams of protein, f grams of fat, and c grams of carbohydrate, which of the following expresses f in terms of p and c ?
Energy per Gram of Typical Macronutrients

The table above gives the typical amounts of energy per gram, expressed in both food calories and kilojoules, of the three macronutrients in food

The graph of a line in the xy-plane has a positive slope and intersects the y-axis at a point that has a negative y-coordinate. Which of the following could be an equation of the line?

If x is a solution to the given equation, which of the following is a possible value of x + 5 ?

In a right triangle, the tangent of one of the two acute angles is . What is the tangent of the other acute angle?

The function A(t) models the number of liters of a fluid in a tank after t hours. Which of the following models the number of liters of the fluid in the tank after m minutes?

For the linear function f , the table above gives some values of x and their corresponding values f(x), where c is a constant. Which of the following equations defines f ?

Refer to the following information.
If x food calories is equivalent to k kilojoules, of the following, which best represents the relationship between x and k ?
Energy per Gram of Typical Macronutrients

The table above gives the typical amounts of energy per gram, expressed in both food calories and kilojoules, of the three macronutrients in food

A bag containing 10,000 beads of assorted colors is purchased from a craft store. To estimate the percent of red beads in the bag, a sample of beads is selected at random. The percent of red beads in the bag was estimated to be 15%, with an associated margin of error of 2%. If r is the actual number of red beads in the bag, which of the following is most plausible?

Club Participation in the 2014-2015 School Year

Of all juniors and seniors who attended a particular high school during the 2014 -2015 school year, 149 participated in the clubs listed in the table above. Each of the 149 students participated in only one of the four school clubs listed. The table shows the distribution of the 149 students by class and club participation. Of the number of juniors and seniors in the drama club, the 25% who walked to school represents  of the total number of juniors and seniors who walked to school. How many juniors and seniors walked to school?

The graph of the exponential function g in xy plane passes through the points (0,1), (1,4) and (2,16). Which of the following is NOT true?

Which of the following is the value of y in the solution (x, y) to the system of equations above?

Club Participation in the 2014-2015 School Year

Of all juniors and seniors who attended a particular high school during the 2014 -2015 school year, 149 participated in the clubs listed in the table above. Each of the 149 students participated in only one of the four school clubs listed. The table shows the distribution of the 149 students by class and club participation.
The band was composed of freshmen, sophomores, juniors, and seniors. If 30% of the students in the band were juniors, how many students were in the band?