# 8th Grade Practice Test - Divisional STEM ?· 8th Grade Practice Test - Divisional STEM Competition…

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TAME Divisional STEM Competition 8h Grade Practice Test

Page 1 of 12

8th Grade Practice Test - Divisional STEM Competition

Answer the following questions by marking the BEST answer on the answer sheet.

1. Mr. Gibbs, a teacher in the middle school, will eliminate each students lowest quiz grade when he computes grades at the end of the semester. How will the procedure affect the mean and median for an individual

student whose grades are 95, 90, 85, and 58?

a. It will affect the mean more than the median. b. It will affect the median more than the mean. c. It will affect the mean and median equally. d. It will have no effect on either the mean or the median.

2. Shannon needs to wrap a gift in the shape of a cube that has a side length of 1.5 ft. What is the least amount of paper she needs to cover the gift?

a. 16.8 ft2 b. 13.5 ft2 c. 8.45 ft2 d. 3.375 ft2

3. The table to the right shows the population of Texas from 1900 to 2000. Which of the following is true, based on the data above?

a. The population of Texas doubled from 1980 to 2000. b. The population of Texas in 1990 was 4 times the population in 1920. c. The population of Texas more than tripled from 1900 to 1960. d. The population of Texas in 1980 was 2 times the population in 1950.

4. Jaine used three straws of different lengths to create triangles. Which statement is true about the triangle she created with side lengths 5, 6, and 10?

a. It is a right triangle because the hypotenuse is shorter than the sum of the other 2 sides. b. It is a right triangle because a + b = c c. It is a right triangle because it proportional to a 3, 4, 5 triangle. d. It is a not a right triangle because a + b c

5. Which answer gives the correct side lengths to the triangle to the right?

a. 2,2,4 b. 2, 2, 2 c. 1, 1, 2 d. 4,4,8

Copyright Texas Alliance for Minorities in Engineering (TAME) 01.19.2017

TAME Divisional STEM Competition 8h Grade Practice Test

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6. What is the relationship between the volume of the cone and the volume of the cylinder as shown below?

a. The volume of the cone is 1/3 of the volume of the cylinder. b. The volume of the cone is 1/2 of the volume of the cylinder. c. The volume of the cone is 2/3 of the volume of the cylinder. d. The volume of the cone is 4/3 of the volume of the cylinder.

7. The Squeaky Clean Car Wash charges by the minute, as shown by the chart below. Explain how you know the relationship is linear.

Squeaky Clean Car Wash Charges

Time (min) 5 10 15 20 25

Charge $8 $13 $18 $23 $28

a. The charge decreases by a set amount as the time increases. b. Both the charge and time increase by 8. c. As the time increases by a set amount, the charge also increases by a set amount. d. None of the above

8. From which equation could the chart below be created?

a. y = 4(x - 7) + 6 b. y = -3x 8 c. y = x(3x + 2) d. y = 4 - 3x

x -3 -1 3

y 3 -5 51

9. At a water park, the daily profit from the concession stands depends on the number of park visitors. The equation p= 2.50v 500 gives the estimated profit p in dollars when v people visit the park. For what number

of visitors will the profit be about $2,000?

a. 200 b. 400 c. 600 d. 1000

10. Which rule describes a translation of the original figure?

I. (x,y) (x + 2, y -3) II. (x,y) (2x, y)

III. (x,y) (x + 1, 3y) IV. (x,y) (x -2, y + 1)

a. II and III b. I only c. I and IV d. All of the above

11. One property of most alkali metals is that they are ________.

a. not very useful elements.

b. too hard to cut with a knife.

c. very reactive with other elements.

d. found in nature uncombined with other elements.

Copyright Texas Alliance for Minorities in Engineering (TAME) 01.19.2017

TAME Divisional STEM Competition 8h Grade Practice Test

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12. Which of the following models represents the correct number of valence electrons in an argon atom? You may use a periodic table to solve this problem.

a b c d

13. Which of the following is the LEAST likely to react?

a. an atom with 2 valence electrons

b. an atom with 4 valence electrons

c. an atom with 7 valence electrons

d. an atom with 8 valence electrons

14. Which is an example of the use of activation energy?

a. plugging in an iron

b. playing basketball

c. holding a lit match to paper

d. eating

15. When reactant particles collide more often, ________.

a. the reaction rate remains the same

b. the reaction rate decreases

c. the reaction rate increases

d. None of the above

16. Which of the following is the formula for sodium fluoride?

a. SF b. SFl c. NaF d. NaFl

17. Below are diagrams of sound waves moving from one room into another through a door. Each sound wave moves from left to right. Diagram B best illustrates that ____ when you are in the next room.

a. high pitches are easier to hear

b. high pitches are harder to hear

c. low pitches are harder to hear

d. low pitches are easier to hear

18. The rumbling sound of thunder is heard when lightning strikes far away because ________.

a. thunder has only high frequencies.

b. thunder has only low frequencies.

c. only high-frequency waves can diffract around trees, buildings, hills, and other barriers.

d. only low-frequency waves can diffract around trees, buildings, hills, and other barriers.

Copyright Texas Alliance for Minorities in Engineering (TAME) 01.19.2017

TAME Divisional STEM Competition 8h Grade Practice Test

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19. Watson and Crick ________.

a. collected peppered moths to study their coloring.

b. took X-ray pictures of DNA.

c. made models to find out DNA's shape.

d. bred pea plants to study the patterns of heredity.

20. A symbiotic relationship in which one organism benefits and the other is unaffected is called ________.

a. parasitism b. commensalism c. mutualism d. organism

21. Which value below is not true for the inequality -4x + 5 13?

a. -2 b. -4 c. 2 d. 4

22. Choose the correct statement to describe the correlation in the graph?

a. It represents a positive correlation. b. There is no correlation because it does not start at the origin. c. It represents a negative correlation. d. There is no correlation due to the outliers.

23. A hexagon has two sides with lengths 2x +1, two sides with lengths 3x -2, and two sides with lengths 4x -5. Express the perimeter of the hexagon in terms of x.

a. 18x -12 b. 9x -6 c. 18x3 + 10 d. 18x -16

24. Evaluate 3

3() if x = 5 and y = 3.

a. 0 b. 2 c. 3 d. 6

25. Simplify 12(1

4 +

1

3)

1

2(12 6).

a. -3x + 7 b. 3x + 7 c. 4 d. -5x + 3

26. Solve 3w 13 = 1

4(52 12w).

a. 41

3 b. -1 c. no solution d. all real numbers

Copyright Texas Alliance for Minorities in Engineering (TAME) 01.19.2017

TAME Divisional STEM Competition 8h Grade Practice Test

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27. Nick worked 16 hours last week. He earned $5 per hour at a local restaurant and $5.50 per hour at a grocery store. If he earned a total of $82, how many hours did he work at the grocery store?

a. 8 h b. 4 h c. 12 h d. 2 h

28. Solve for y in the equation +

2 = a.

a. = 2+

b. =

2

c. = 2 d. = 2 +

29. Which ordered pair is a solution of 3x 2y = 5?

a. (1, -1) b. (2, 1) c. (-1, 1) d. (-2, 1)

30. Which answer shows the domain and range of the curve that is graphed?

a. 0 4 and 0 36 b. 0 36 and 0.5 3.5 c. 0.5 3.5 and 0 36 d. 1 3.5and 0 36

31. A tapeworm lives inside the intestines of a cow and feeds by absorbing food that the cow has already digested. This is an example of ________.

a. competition b. commensalism c. mutualism d. parasitism

32. As soon as bleeding occurs, platelets ________.

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