Correct Answer: B

Rationale: To convert a fraction to a decimal, divide the numerator by the denominator. In this case, 1 · 5 = 0.2. Therefore, the correct answer is B. Choice A (0.5) is incorrect because the decimal form of 1/5 is not 0.5. Choice C (1.5) is incorrect as it is the sum of 1 and 0.5, not the decimal form of 1/5. Choice D (0.15) is incorrect as it is the decimal form of 15/100, not 1/5.

Correct Answer: A

Rationale: To add fractions with different denominators, find a common denominator. In this case, the common denominator of 4 and 8 is 8. Convert 1/4 to 2/8, then add it to 3/8. The sum is 5/8. Choice B (7/12) is incorrect as it is the result of adding 1/3 + 1/4. Choice C (2/3) is incorrect as it is the result of adding 3/8 + 1/4. Choice D (1/2) is incorrect as it is the result of adding 1/4 + 1/4.

Correct Answer: B

Rationale: Since each syringe holds 3ml of liquid, to measure 15ml of liquid, you would need to divide 15ml by 3ml/syringe. This calculation gives you 5 syringes needed to measure 15ml of liquid. Choice A (3 syringes) is incorrect because 3 syringes would only hold 9ml of liquid, not 15ml. Choice C (7 syringes) and Choice D (9 syringes) are incorrect as they would result in an excess amount of liquid, which is not needed.

Correct Answer: A

Rationale: To convert a fraction to a decimal, divide the numerator by the denominator. In this case, 3 divided by 4 is equal to 0.75. Therefore, the correct answer is A. Choices B, C, and D are incorrect because they do not represent the equivalent decimal value of 3/4. 0.5 is the decimal equivalent of 1/2, 0.65 is the decimal equivalent of 13/20, and 0.85 is the decimal equivalent of 17/20.

Correct Answer: C

Rationale: The correct answer is C (16.60%). When rolling a standard 6-sided die, the probability of getting a 5 is 1/6 or approximately 16.6%. Choice A (50%) is incorrect as it represents the probability of getting a specific number on a coin flip, not a die roll. Choice B (20%) is incorrect as it does not reflect the probability of rolling a 5 on a standard die. Choice D (83.30%) is incorrect as it is the complement of the probability of rolling a 5, which is not asked in the question.