Correct Answer: B

Rationale: To find the sum of numbers from 1 to 6, we add them together: 1 + 2 + 3 + 4 + 5 + 6 = 21. Therefore, the correct answer is 21. Choice A (30) is incorrect because it is not the sum of the numbers 1 to 6. Choice C (15) is incorrect as it is the sum of numbers 1 to 5. Choice D (13) is incorrect as it is the sum of numbers 1 to 4, not 1 to 6.

Correct Answer: C

Rationale: If \(2x = 6\), then solving for \(x\), we have \(x = \frac{6}{2} = 3\). So, if \(x = 3\), then \(x+1 = 3+1 = 4\). Therefore, the value of \(x+1\) would be 4.

Correct Answer: C

Rationale: The correct answer is C. Sarah buys one red can of paint every month for four months. Therefore, if she continues this pattern for four months, she would have bought a total of 4 red cans. Choices A, B, and D are incorrect because they do not reflect the total number of red cans accumulated over the specified period of four months.

Correct Answer: A

Rationale: The relative error is calculated using the formula: (|Measured Value - True Value| / True Value) * 100%. Substituting the values given, we have (|36 - 75| / 75) * 100% = (39 / 75) * 100% ≈ 0.52 * 100% = 0.52%. Therefore, the relative error in measurement is approximately 0.52%. Choice A is correct because it reflects this calculation. Choice B is incorrect as it represents a lower relative error than the actual value obtained. Choice C is incorrect as it overestimates the relative error. Choice D is incorrect as it underestimates the relative error.

Correct Answer: D

Rationale: A pie chart is the most appropriate choice for displaying the percentages of time spent on different tasks during the workday because it visually represents parts of a whole. In this case, each task's percentage represents a part of the entire workday, making a pie chart an ideal way to compare these percentages. Line plots, bar graphs, and line graphs are not suitable for showing percentages of a whole; they are more commonly used for tracking trends, comparing values, or showing relationships between variables but do not efficiently represent parts of a whole like a pie chart does.