How many grams are in 8 kilograms?

Correct Answer: D

Rationale: To convert kilograms to grams, you multiply by 1,000 since there are 1,000 grams in a kilogram. Therefore, 8 kilograms = 8 x 1,000 = 8,000 grams. The correct answer is 8,000 grams, which is option D. Choices A and C are incorrect as they incorrectly multiply by 10,000 instead of 1,000. Choice B is incorrect as it divides 8 by 10 instead of multiplying by 1,000.

Correct Answer: A

Rationale: Subtract the whole numbers and then subtract the fractions: 12 - 7 4\5 = 5 1\5.

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: B

Rationale: To find the total calories consumed in 3 meals, you multiply the number of meals by the calories per meal: 3 meals x 500 calories/meal = 1500 calories. Therefore, the correct answer is 1500 calories. Choice A (1000 calories) is incorrect because it miscalculates the total calories. Choice C (2000 calories) is incorrect as it overestimates the total calories. Choice D (500 calories) is incorrect as it represents the calories consumed in a single meal, not in 3 meals.

Correct Answer: B

Rationale: To convert a decimal to a fraction, the decimal is written without the decimal point as the numerator. For 0.26, this gives 26. The denominator is based on the place value of the decimal, which is the number of decimal places the decimal has. In this case, 0.26 has two decimal places, so the fraction is 26/100, which simplifies to 13/50. Choice A (7/8) is incorrect as it does not represent 0.26. Choice C (26/100) is also incorrect because it is not in its simplest form. Choice D (1/3) is incorrect as it is not the correct equivalent fraction for 0.26.

Correct Answer: A

Rationale: To find out how many minutes Kevin will take to wash 100 cars, set up a proportion: 30 cars is to 15 minutes as 100 cars is to x minutes. Cross multiplying gives 30x = 1500. Solving for x, x = 1500 / 30 = 50. Therefore, it will take Kevin 50 minutes to wash 100 cars. Choice A is correct. Choice B, C, and D are incorrect as they do not correctly calculate the time needed based on the given information.

Correct Answer: A

Rationale: The correct answer is A: 1/6. A six-sided die has one face with a '2' out of six possible outcomes (numbers 1 to 6). Therefore, the probability of rolling a 2 is 1/6. Choices B, C, and D are incorrect because they do not reflect the specific probability of rolling a 2 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: A

Rationale: The correct subtraction is 12.02 - 9.99 = 2.03. Therefore, the correct answer is A. Choice B, 2.21, is incorrect as it does not result from the given subtraction. Choice C, 3.17, is also incorrect. Choice D, 7.97, is incorrect as well. Thus, A is the only correct answer.