Correct Answer: A

Rationale: The mode of a set of numbers is the value that appears most frequently. In the distribution shown in the table, the number '1' occurs more times than any other number, making it the mode. Choices B, C, and D are incorrect because they do not represent the number that occurs most frequently in the dataset.

Correct Answer: A

Rationale: A proportional relationship is one in which two quantities vary directly with each other. In choice A, the amount deposited per month is directly proportional to the initial deposit. The relationship can be represented as y = 125x + 150, where x is the number of months and y is the total amount in the account. Choices B and C involve additional fixed amounts or variable costs that do not maintain a constant ratio, making them non-proportional relationships. Choice D refers to a constant speed of driving, which is not a proportional relationship as it does not involve varying quantities that change in direct proportion.

Correct Answer: B

Rationale: To find the increase in temperature after 20 minutes, calculate how many 3-minute intervals are in 20 minutes (20 · 3 = 6.66, rounding to 7 intervals). Then, multiply the temperature increase per interval (2 °C) by the number of intervals (7 intervals), giving a total increase of 14 °C. Therefore, after 20 minutes, the temperature of the water would have increased by approximately 14 °C. Choice A, 10 °C, is incorrect as it underestimates the total increase. Choice C, 15 °C, is incorrect as it overestimates the total increase. Choice D, 35 °C, is incorrect as it represents the initial temperature of the water, not the increase in temperature.

Correct Answer: A

Rationale: The first midwife contributes $2000. She spends $800 on rent and utilities. After paying for rent and utilities, $1200 remains. Half of this amount, which is $600, is saved for incidental expenditures. Therefore, the first midwife spends the remaining $600 on purchasing medical supplies each month. Choice A, $600, is the correct answer. Choices B, C, and D are incorrect as they do not accurately reflect the amount spent on medical supplies as calculated in the given scenario.

Correct Answer: B

Rationale: The correct equation that describes the relationship between x and y based on the chart is y = 3x. This is because each y-value in the chart is 3 times the x-value. Choice A (x = 3y) is incorrect as it implies x is 3 times y, which is the opposite of the relationship shown in the chart. Choice C (y = 1/3x) is incorrect since the relationship in the chart indicates y is 3 times x, not a third of x. Choice D (x/y = 3) is incorrect as it represents a ratio between x and y equal to 3, which is not in line with the relationship depicted in the chart.