Correct Answer: C

Rationale: To find the perimeter of a rectangle, you add the lengths of all sides. The formula for the perimeter of a rectangle is 2 * (length + width). In this case, the length is 15cm and the width is 20cm. Therefore, the perimeter = 2 * (15cm + 20cm) = 65cm. Choice A (30cm), Choice B (55cm), and Choice D (75cm) are incorrect as they do not correctly calculate the perimeter of the given rectangle.

Correct Answer: C

Rationale: The symbol '::' represents a proportion in which the first pair of numbers is related to the second pair of numbers. To solve for x in the proportion 2 : 5 :: 64 : x, you can set up a proportion equation: 2/5 = 64/x. Cross-multiplying gives you 2x = 5 * 64, which simplifies to 2x = 320. Dividing both sides by 2, you get x = 160. Therefore, x = 128 is the correct answer. Choice A (32) is incorrect as it is not the result of solving the proportion equation. Choice B (70) is incorrect as it is not related to the given proportion. Choice D (160) is a common mistake made by wrongly interpreting the equation; the correct value of x is 128.

Correct Answer: B

Rationale: Rationale: Given that 1 teaspoon is equal to 5ml, and the medication dosage is listed as 1/2 teaspoon, we need to find half of 5ml. 1/2 of 5ml = 5ml / 2 = 2.5ml Therefore, the equivalent dosage in milliliters for 1/2 teaspoon is 2.5ml.

Correct Answer: B

Rationale: To convert quarts to pints, we know that 1 quart is equivalent to 2 pints. Therefore, to find out how many pints are in 4 quarts, we multiply 2 pints by 4, which equals 8 pints. Hence, the correct answer is 8 pints. Choice A (2 pints) is incorrect because it represents the conversion of 1 quart, not 4 quarts. Choice C (16 pints) and Choice D (32 pints) are incorrect as they miscalculate the conversion by not considering the correct conversion factor of 2 pints per quart.

Correct Answer: A

Rationale: To find 40% of 150, you multiply 150 by 0.40 (which represents 40% in decimal form). This calculation results in 60. Therefore, choice A, 60, is the correct answer. Choice B (65), choice C (70), and choice D (85) are incorrect as they do not reflect the accurate calculation for finding 40% of 150.