Correct Answer: B

Rationale: To find the total number of balls needed to make the yellow balls 65% of the total, let x be the total number of balls required. Initially, there are 15 yellow balls. The total number of balls would be 15 + x after adding more yellow balls. The equation to represent this is: (15 + x) / (15 + x) = 0.65 (since the yellow balls need to constitute 65% of the total). Solving this equation gives x = 50, indicating that 50 more yellow balls need to be added to the basket to reach the desired percentage. Choice A, C, and D are incorrect as they do not accurately represent the additional yellow balls needed to achieve the specified percentage.

Correct Answer: C

Rationale: To convert teaspoons to milliliters, we use the conversion factor of 1 teaspoon = approximately 4.93 milliliters. Multiplying 2 teaspoons by 4.93 gives us 9.86 milliliters. Therefore, the correct answer is 9.86 milliliters. Choice A (4.3 milliliters) is incorrect as it doesn't align with the conversion factor. Choice B (9 milliliters) is incorrect because it doesn't consider the precise conversion factor. Choice D (4 milliliters) is incorrect as it doesn't account for the accurate conversion from teaspoons to milliliters.

Correct Answer: C

Rationale: To subtract 7/8 from 2 & 5/8, you need to borrow 1 whole from the 2, making it 1 whole and 13/8. Then, subtracting 7/8 from 13/8 results in 6/8, which simplifies to 3/4. Therefore, the answer is 1 & 3/4. Choice A (1 & 5/8) is incorrect as the correct answer is 1 & 3/4. Choice B (1 & 6/8) can be simplified to 1 & 3/4, which is the correct answer. Choice D (1 & ¼) is incorrect as the subtraction result is greater than 1, making the whole number part 1.

Correct Answer: A

Rationale: To convert the fraction 7/8 into a decimal, you divide 7 by 8, which equals 0.875. To express this decimal as a percentage, you multiply it by 100 to get 87.5%. Choices B, C, and D are incorrect because they do not represent the correct conversion of the fraction 7/8 into a decimal and a percent.

Correct Answer: A

Rationale: To convert meters to millimeters, you multiply by 1000 since there are 1000 millimeters in 1 meter. Therefore, 5 meters multiplied by 1000 equals 5000 millimeters. Choice A is correct as it represents the accurate conversion from meters to millimeters. Choices B, C, and D are incorrect as they do not provide the correct conversion factor from meters to millimeters.