Which of the following is listed in order from least to greatest?
- A. -2 3/4, -2 7/8, -1/5, 2/5, 1/8
- B. -1/5, 1/8, 2/5, -2 3/4, -2 7/8
- C. -2 7/8, -2 3/4, -1/5, 1/8, 2/5
- D. 1/8, 2/5, -1/5, -2 7/8, -2 3/4
Correct Answer: C
Rationale: To determine the order from least to greatest, we can convert all fractions and mixed numbers to decimals or use a least common denominator. Converting the fractions in Choice C to decimals, we get -2.875, -2.75, -0.2, 0.125, and 0.4 when reading from left to right. Negative integers with larger absolute values are less than negative integers with smaller absolute values. Therefore, the correct answer is Choice C. Choices A, B, and D are incorrect because they do not present the numbers in the correct order from least to greatest when converted to decimals or compared using common denominators.
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Simplify the following expression: 0.0178 2.401
- A. 2.0358414
- B. 0.0427378
- C. 0.2341695
- D. 0.348324
Correct Answer: B
Rationale: To simplify the expression 0.0178 2.401, you multiply the two numbers to get the result. Therefore, 0.0178 2.401 = 0.0427378. Choice A (2.0358414), Choice C (0.2341695), and Choice D (0.348324) are incorrect as they do not represent the correct result of the multiplication operation.
Dr. Lee observed that 30% of all his patients developed an infection after taking a certain antibiotic. He further noticed that 5% of that 30% required hospitalization to recover from the infection. What percentage of Dr. Lee's patients were hospitalized after taking the antibiotic?
- A. 1.50%
- B. 5%
- C. 15%
- D. 30%
Correct Answer: A
Rationale: To find the percentage of Dr. Lee's patients hospitalized after taking the antibiotic, we need to calculate 30% of 5%. First, convert 30% and 5% to decimals: 30% = 0.30 and 5% = 0.05. Multiply 0.30 by 0.05 to get 0.015. To convert 0.015 to a percentage, multiply by 100, resulting in 1.5%. Therefore, only 1.50% of Dr. Lee's patients were hospitalized after taking the antibiotic. Choice A is correct. Choice B (5%) is incorrect as it represents the percentage of patients who developed an infection and not those hospitalized. Choices C (15%) and D (30%) are also incorrect percentages as they do not accurately reflect the proportion of hospitalized patients in this scenario.
The first midwife uses 2/5 of her monthly contribution to pay for rent and utilities. She saves half of the remainder for incidental expenditures, and uses the rest of the money to purchase medical supplies. How much money does she spend on medical supplies each month?
- A. $600
- B. $800
- C. $1,000
- D. $1,200
Correct Answer: A
Rationale: The first midwife contributes $2000. She spends $800 on rent and utilities. After paying for rent and utilities, $1200 remains. Half of this amount, which is $600, is saved for incidental expenditures. Therefore, the first midwife spends the remaining $600 on purchasing medical supplies each month. Choice A, $600, is the correct answer. Choices B, C, and D are incorrect as they do not accurately reflect the amount spent on medical supplies as calculated in the given scenario.
What is the surface area of the cylinder shown below?
- A. 602.9 cm²
- B. 904.3 cm²
- C. 1,408.7 cm²
- D. 1,507.2 cm²
Correct Answer: D
Rationale: The surface area of a cylinder can be calculated using the formula: S = 2πr² + 2πrh, where r is the radius and h is the height. Substituting the values for radius (12) and height (8) into the formula: S = 2π(12)² + 2π(12)(8). S = 2π(144) + 2π(96). S = 288π + 192π. S = 480π ≈ 1507.964. Therefore, the surface area of the cylinder is approximately 1507.2 square centimeters. Choice A, 602.9 cm², is incorrect as it is significantly lower than the correct value. Choice B, 904.3 cm², is also incorrect as it does not match the calculated surface area. Choice C, 1,408.7 cm², is incorrect as it does not align with the calculated value of the surface area.
Which of the following describes a proportional relationship?
- A. Johnathan opens a savings account with an initial deposit of $150 and deposits $125 per month
- B. Bruce pays his employees $12 per hour worked during the month of December, as well as a $250 bonus
- C. Alvin pays $28 per month for his phone service plus $0.07 for each long-distance minute used
- D. Kevin drives 65 miles per hour
Correct Answer: A
Rationale: A proportional relationship is one in which two quantities vary directly with each other. In choice A, the amount deposited per month is directly proportional to the initial deposit. The relationship can be represented as y = 125x + 150, where x is the number of months and y is the total amount in the account. Choices B and C involve additional fixed amounts or variable costs that do not maintain a constant ratio, making them non-proportional relationships. Choice D refers to a constant speed of driving, which is not a proportional relationship as it does not involve varying quantities that change in direct proportion.