Solve for x: x/5 = 3/10.

Correct Answer: D

Rationale: To solve for x when x/5 = 3/10, you need to cross-multiply. This gives you 10x = 5 3. Simplifying further, you get x = 15/10, which reduces to x = 1.5. Therefore, the correct answer is x = 1.5. Choices A, B, and C are incorrect because they do not match the correct calculation for x.

Correct Answer: A

Rationale: To produce 24 eggs in 24 hours, 4 times the number of chickens needed to produce 6 eggs is required. Since it takes 2 chickens to produce 6 eggs, 8 chickens are needed to produce 24 eggs in the same time frame. Choice B, 12 chickens, is incorrect because it doesn't consider the proportionality between chickens and eggs. Choice C, 18 chickens, is incorrect as it overestimates the number of chickens needed. Choice D, 6 chickens, is incorrect as it doesn't account for the increased number of eggs required.

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: C

Rationale: To calculate the total number of words typed in 20 minutes, multiply the typing speed per minute (45 words) by the duration in minutes (20 minutes): 45 words/min 20 min = 900 words. Therefore, the correct answer is 900 words. Choices A, B, and D are incorrect because they do not reflect the accurate calculation based on the given information.

Correct Answer: B

Rationale: The correct answer is B: Decimal. The decimal system, also known as the base-10 system, is the standard system for denoting integer and non-integer numbers in the United States and many other countries. In the decimal system, numbers are represented using 10 digits (0-9). Choices A, C, and D are incorrect. Tertiary, Napoleonic, and Binary number systems are not commonly used for general number representation in the United States.

Correct Answer: A

Rationale: The correct answer is A, 50%. A standard six-sided die has three even numbers (2, 4, 6) out of six possible outcomes. The probability of rolling an even number is therefore 3 out of 6, which simplifies to 50%. Choices B, C, and D are incorrect because they do not accurately reflect the probability of rolling an even number on a six-sided die.

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.

Correct Answer: D

Rationale: The correct answer is D, 60. To find 50% of 120, you multiply 0.5 by 120: 0.5 x 120 = 60. Choice A and B are incorrect as they are duplicates. Choice C, 70, is incorrect because it is not the result of calculating 50% of 120.

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.