Nokea
Solve for x: 3(x - 5) = 2(x + 3)
- A. x = 3
- B. x = 6
- C. x = 9
- D. x = 12
Correct Answer: A
Rationale: To solve the equation 3(x - 5) = 2(x + 3) for x, start by distributing the terms inside the parentheses. This gives you 3x - 15 = 2x + 6. Next, combine like terms by moving all terms with x to one side and the constants to the other side. Subtracting 2x from both sides gives x - 15 = 6. Finally, adding 15 to both sides results in x = 21. Therefore, the correct answer is A: x = 3. Choices B, C, and D are incorrect as they do not result from the correct calculations of the equation.
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A quantity increases from 40 to 60. Express this increase as a percentage.
- A. 26%
- B. 50%
- C. 35%
- D. 12%
Correct Answer: B
Rationale: To calculate the percentage increase, use the formula:
Percentage Increase = ((New Value - Original Value) / Original Value) x 100
Substitute the values:
((60 - 40) / 40) x 100 = (20 / 40) x 100 = 0.5 x 100 = 50%
Therefore, the correct answer is 50%.
Choice A (26%) is incorrect as the percentage increase is not 26%. Choice C (35%) is incorrect as the percentage increase is not 35%. Choice D (12%) is incorrect as the percentage increase is not 12%.
On a floor plan drawn at a scale of 1:100, the area of a rectangular room is 50 cm². What is the actual area of the room?
- A. 500 m²
- B. 50 m²
- C. 5000 cm²
- D. 500 cm²
Correct Answer: D
Rationale: The scale of 1:100 means that 1 cm² on the floor plan represents 100 cm² in real life. To find the actual area of the room, you need to multiply the area on the floor plan by the square of the scale factor. Since the scale is 1:100, the scale factor is 100. Therefore, 50 cm² on the floor plan represents 50 * 100 = 5000 cm² in real life. Choice A (500 m²) is incorrect as it converts the area from cm² to m² without considering the scale factor. Choice B (50 m²) is incorrect as it does not account for the scale factor. Choice C (5000 cm²) is incorrect as it gives the area on the floor plan, not the actual area.
How many kilometers is 4382 feet?
- A. 1.336 kilometers
- B. 14.376 kilometers
- C. 1.437 kilometers
- D. 13.336 kilometers
Correct Answer: A
Rationale: To convert feet to kilometers, you need to divide the number of feet by 3280.84 (the number of feet in a kilometer). Therefore, 4382 feet is equal to 4382/3280.84 ≈ 1.336 kilometers. Choice B, 14.376 kilometers, is incorrect as it seems to be a miscalculation. Choice C, 1.437 kilometers, is also incorrect, as it is slightly off from the correct conversion. Choice D, 13.336 kilometers, is significantly higher than the correct answer and does not align with the conversion factor.
When the sampling distribution of means is plotted, which of the following is true?
- A. The distribution is approximately normal.
- B. The distribution is positively skewed.
- C. The distribution is negatively skewed.
- D. There is no predictable shape to the distribution.
Correct Answer: A
Rationale: When the sampling distribution of means is plotted, the distribution tends to be approximately normal, especially as the sample size increases. This phenomenon is described by the Central Limit Theorem, which states that the sampling distribution of the sample mean will be normally distributed regardless of the shape of the original population distribution as long as the sample size is sufficiently large. Choices B and C are incorrect because sampling distributions of means are not skewed. Choice D is incorrect because there is a predictable shape to the distribution, which is approximately normal.
Solve the following: 4 x 7 + (25 - 21)²
- A. 512
- B. 36
- C. 44
- D. 22
Correct Answer: B
Rationale: First, solve the expression inside the parentheses:
25
−
21
=
4
25−21=4
Then, square the result from the parentheses:
4
2
=
16
4
2
=16
Perform the multiplication:
4
7
=
28
47=28
Finally, add the results:
28
+
16
=
44
28+16=44