X/4 = 9/x, solve for x.
- A. x = 6
- B. x = 3
- C. x = 9
- D. x = 2
Correct Answer: A
Rationale: To solve X/4 = 9/x, cross multiply to get x^2 = 36. Taking the square root of both sides gives x = 6. Choice A is correct because x = 6 satisfies the equation x^2 = 36. Choices B, C, and D are incorrect as they do not satisfy the equation when substituted back into it.
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The height of a building is 150 feet. If each floor of the building is 12 feet high, how many floors are in the building?
- A. 13 floors
- B. 15 floors
- C. 10 floors
- D. 18 floors
Correct Answer: A
Rationale: To determine the number of floors in the building, divide the total height of the building (150 feet) by the height of each floor (12 feet). 150 feet · 12 feet per floor = 12.5 floors. Since floors cannot be in fractions, the answer is rounded down to the nearest whole number, which is 13 floors. Therefore, the correct answer is A: 13 floors. Choice B (15 floors) is incorrect because the calculation results in 12.5 floors, which should be rounded down. Choices C (10 floors) and D (18 floors) are incorrect as they do not accurately reflect the division result and rounding down process.
A lab test result shows a blood glucose level of 5.5 millimoles per liter (mmol/L). What is the equivalent level in milligrams per deciliter (mg/dL)?
- A. 55 mg/dL
- B. 5.5 mg/dL
- C. 0.55 mg/dL
- D. 550 mg/dL
Correct Answer: A
Rationale: To convert the blood glucose level from millimoles per liter (mmol/L) to milligrams per deciliter (mg/dL), we need to perform a double conversion. 1 millimole is equivalent to 180.15 milligrams, and 1 liter is equal to 10 deciliters. First, multiply the glucose level (5.5 mmol/L) by the conversion factor for millimoles to milligrams (180.15 mg/mmol), then divide by the conversion factor for liters to deciliters (10 dL/L): 5.5 mmol/L * 180.15 mg/mmol / 10 dL/L ≈ 55 mg/dL. Therefore, the equivalent blood glucose level in mg/dL is 55. Choice A is correct. Choice B is incorrect as it does not account for the conversion factors properly. Choices C and D are significantly off as they do not follow the correct conversion calculations.
What is the result of adding 1/2 + 4/5?
- A. 1 3/10
- B. 1/2/2024
- C. 1 2/5
- D. 1 1/5
Correct Answer: A
Rationale: To add fractions, you need a common denominator. In this case, the common denominator is 10. So, 1/2 + 4/5 = 5/10 + 8/10 = 13/10 = 1 3/10. Therefore, the correct answer is A: 1 3/10. Choice B, 1/2/2024, is incorrect as it does not represent the sum of the fractions given. Choice C, 1 2/5, is incorrect as it does not match the sum calculated. Choice D, 1 1/5, is incorrect as it does not reflect the correct sum of the fractions provided.
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.
What is the result of adding 5 2/9 and 1 2/9?
- A. 6 4/9
- B. 7 5/9
- C. 7
- D. 5 2/9
Correct Answer: A
Rationale: To add mixed numbers with fractions, first add the whole numbers together: 5 + 1 = 6. Then add the fractions: 2/9 + 2/9 = 4/9. Combining the whole number and the fraction parts gives 6 4/9. Therefore, the correct answer is 6 4/9. Choice B (7 5/9) is incorrect as the fractions were not added correctly. Choice C (7) is incorrect as it does not account for the fractions. Choice D (5 2/9) is one of the original numbers and not the sum of both.