MCAS 2000, 10th Grade Math, Questions 21-24

Click here for a PDF version of this set of questions. The PDF format may offer a clearer version when you print these pages (requires the free Adobe Acrobat Reader).

Your printer may also be able to print directly from the version which is now appearing on your computer screen.


Question #21 (Open Response Question)

An automobile is purchased for $18,000. Its value decreases each year according to the following schedule:

a. What is the value of this car at the end of one year? Explain or show how you found your answer.

b. During which year will the car's value decrease to less than half its original price? Explain or show how you found your answer.

c. Suppose the value of another car, which also costs $18,000, decreases at the rate of 25% each year. Which car would have the greater value 3 years after it was purchased? Explain or show how you found your answer.


Question #22 (Open Response Question)

The power, P, generated in an hour by the windmill on Jones's farm is proportional to the cube of the wind speed, V, as shown by the formula

P = 0.015V3

where P is measured in watts and V is measured in miles per hour.

a. Calculate the amount of power that the Jones's windmill would generate in an hour with a steady wind of 8 mph.

b. What wind speed is needed for the windmill to produce 120 watts of power in an hour? Explain or show how you found your answer.

c. Matt says that if the wind blew at 4 mph for one hour and then 12 mph for another hour the amount of power generated by the windmill would be the same as the amount generated by an 8 mph wind in two hours. Laurel disagrees. Who is correct? Justify your answer mathematically.


Question #23

Use the figure on the right to answer question 23.

Which diagram could not possibly show how the figure looks when it is viewed directly from above?


Question #24

Which of the following is true for all possible values of x?

A. 3(x + 1) = 3x + 1

B. 2(x + 3) = 2x + 6

C. 4(2x + 1) = 6x + 5

D. 5(3x - 2) = 15x - 7


Go to another week's questions

Return to AchievementInfo.Com Home Page