Correct Answer: B

Rationale: To maintain an overall average of at least 90, Dwayne must aim for a score of 90 on every test. If his current average is below 90, he needs to make up for it by scoring higher on upcoming tests. Choosing 98 ensures that his overall average remains at or above 90. Choice A (89) is below the desired average of 90, so it would not be sufficient. Choices C (95) and D (100) are higher than necessary to maintain an average of at least 90.

Correct Answer: D

Rationale: Xavier starts with 20 apples. He gives half of his apples to his sister Emma, which is 20 · 2 = 10 apples, leaving him with 10 apples. Then, he gives 6 apples to his neighbor Jim, leaving him with 10 - 6 = 4 apples. Using ¾ of his remaining 4 apples for the pie, he uses 3/4 x 4 = 3 apples. Therefore, he has 4 - 3 = 1 apple left at the end of the day. Choice D, 1 apple, is the correct answer. Choices A, B, and C are incorrect because Xavier ends up with 1 apple remaining, not 4, 6, or 2.

Correct Answer: B

Rationale: To maintain an overall average of at least 90, Dwayne must aim for a score of 90 on every test. If his current average is below 90, he needs to make up for it by scoring higher on upcoming tests. Choosing 98 ensures that his overall average remains at or above 90. Choice A (89) is below the desired average of 90, so it would not be sufficient. Choices C (95) and D (100) are higher than necessary to maintain an average of at least 90.

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%.

Correct Answer: A

Rationale: To convert miles to kilometers, the conversion factor is 1 mile ≈ 1.609 kilometers. Therefore, to convert 67 miles to kilometers, you would multiply: 67 miles 1.609 km/mile = 107.703 km. When rounded to three significant digits, this gives 108 km. Therefore, 67 miles is approximately 108 kilometers. Choice A is correct because it is the closest rounded value to three significant digits. Choices B, C, and D are incorrect as they do not match the calculated conversion of 108 km.