Nokea
If x = -2 and m = -3, evaluate: xm - 2m
- A. 12
- B. 6
- C. 8
- D. 10
Correct Answer: A
Rationale: Substitute x = -2 and m = -3 into the expression: (-2) * (-3) - 2 * (-3) = 6 + 6 = 12. Therefore, the correct answer is 12. The mistake in the other choices lies in the calculation. Choice B, 6, is the result of adding the two terms instead of subtracting the second term from the first. Choice C, 8, and Choice D, 10, are also incorrect as they do not follow the correct calculation process.
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A roast was cooked at 325°F in the oven for 4 hours. The internal temperature rose from 32°F to 145°F. What was the average rise in temperature per hour?
- A. 20
- B. 32
- C. 28
- D. 37°F/hr
Correct Answer: C
Rationale: The temperature increased from 32°F to 145°F, resulting in a total increase of 145°F - 32°F = 113°F. Dividing this total increase by the 4 hours of cooking time gives an average rise of 113°F · 4 = 28.25°F per hour, which can be rounded to 28°F per hour. Therefore, the correct answer is 28. Choice A (20) is incorrect because it does not reflect the actual average rise in temperature per hour. Choice B (32) is incorrect as it does not consider the total temperature increase and divide it by the total hours. Choice D (37°F/hr) is incorrect as it does not match the calculated average rise in temperature per hour.
What is the result of the expression 4/5 + 6/7?
- A. 1 23/35
- B. 2 5/7
- C. 1 1/7
- D. 1 3/4
Correct Answer: A
Rationale: To add fractions with different denominators, you first need to find a common denominator. In this case, the common denominator for 5 and 7 is 35. Then, convert each fraction to have a denominator of 35. 4/5 becomes 28/35, and 6/7 becomes 30/35. Adding these fractions together gives 58/35, which simplifies to 1 23/35. Therefore, the correct answer is A, 1 23/35. Choice B, 2 5/7, is incorrect because it does not match the correct result. Choice C, 1 1/7, is incorrect as it is not the simplified form of the sum of the fractions. Choice D, 1 3/4, is incorrect as it is a different result and not the sum of 4/5 and 6/7.
A label states 1 mil contains 500 mg. How many mils are there if there are 1.5 grams?
- A. 9
- B. 2
- C. 3
- D. 5
Correct Answer: C
Rationale: To calculate the number of mils, first, convert 1.5 grams to milligrams (1.5 grams = 1500 mg). Then, since 1 mil contains 500 mg, divide 1500 mg by 500 mg/mil, resulting in 3 mils required to contain 1.5 grams of substance. Choice A, 9, is incorrect because it miscalculates the conversion. Choice B, 2, is incorrect as it does not consider the correct conversion factor. Choice D, 5, is incorrect as it also miscalculates the conversion.
What is (12/15) · (3/5) = ?
- A. 1 1/3
- B. 1 2/3
- C. 2 1/3
- D. 1
Correct Answer: A
Rationale: To divide fractions, you multiply by the reciprocal of the divisor. (12/15) · (3/5) is the same as (12/15) * (5/3). Cancel out common factors to simplify: 12 · 3 = 4, 15 · 5 = 3. So, the expression simplifies to 4/3, which is 1 1/3 in mixed number form. Choice A, 1 1/3, is the correct answer. Choices B, C, and D are incorrect because they do not represent the simplified form of the division of the given fractions.
What is 20% of 150?
- A. 25
- B. 30
- C. 35
- D. 20
Correct Answer: B
Rationale: To find 20% of 150, you need to multiply 150 by 0.20: 150 0.20 = 30. Therefore, 20% of 150 is indeed 30. Choice A (25) is incorrect as it represents 20% of 125, not 150. Choice C (35) is incorrect as it represents more than 20% of 150. Choice D (20) is incorrect as it is the original percentage to find.