Subtract 28 3/4 - 5 5/6.
- A. 22 & 11/12
- B. 23 & 1/2
- C. 34 & 1/12
- D. 22 & 2/3
Correct Answer: A
Rationale: To subtract mixed numbers, find a common denominator. Convert 28 3/4 to 28 9/12. Then, subtract 5 5/6 from 28 9/12 to get 22 11/12. Therefore, 28 3/4 - 5 5/6 = 22 & 11/12, which matches choice A. Choices B, C, and D are incorrect because they do not reflect the correct subtraction result after finding the common denominator and performing the subtraction.
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A doctor orders 1 gram of a medication to be administered intravenously. The available vial contains 200 milligrams per milliliter. How many milliliters of the solution should be drawn up?
- A. 4 milliliters
- B. 5 milliliters
- C. 10 milliliters
- D. 20 milliliters
Correct Answer: B
Rationale: 1 gram is equivalent to 1000 milligrams. The concentration of the medication is 200 milligrams per milliliter. To calculate the volume needed, divide the total amount of medication by the concentration: 1000 mg / 200 mg/mL = 5 mL. Therefore, 5 milliliters of the solution should be drawn up to administer 1 gram of the medication intravenously. Choice A (4 milliliters), Choice C (10 milliliters), and Choice D (20 milliliters) are incorrect because they do not accurately calculate the volume of the solution needed based on the concentration of the medication.
A woman received a bottle of perfume as a present. The bottle contains 3/4 oz of perfume. How many milliliters is this?
- A. 25 mL
- B. 22.5 mL
- C. 15 mL
- D. 20 mL
Correct Answer: B
Rationale: To convert ounces to milliliters, multiply the number of ounces by 29.5735. 3/4 oz 29.5735 ≈ 22.5 mL. Therefore, the correct answer is 22.5 mL. Choice A (25 mL) is incorrect as it does not result from the correct conversion. Choices C (15 mL) and D (20 mL) are also incorrect conversions.
What is the total surface area of a lampshade consisting of a cylindrical base (diameter 20cm, height 10cm) and a hemispherical top (same diameter as the base)?
- A. 785 sq cm
- B. 1130 sq cm
- C. 1570 sq cm
- D. 2055 sq cm
Correct Answer: D
Rationale: To find the total surface area of the lampshade, first calculate the surface area of the cylinder and the hemisphere separately.
1. Surface area of the cylinder = 2πr² + 2πrh = 2π(10)² + 2π(10)(20) = 400π + 400π = 800π cm².
2. Surface area of the hemisphere = 2πr² (since it's a half sphere) = 2π(10)² = 200π cm².
Adding both areas gives the total surface area: 800π + 200π = 1000π cm².
Now, calculate the numerical value: 1000π ≈ 3141.59 cm², which is approximately equal to 2055 cm². Therefore, the correct answer is 2055 sq cm.
Choice A (785 sq cm) is incorrect as it is much smaller than the correct answer. Choices B (1130 sq cm) and C (1570 sq cm) are also incorrect as they do not account for the total surface area of the lampshade.
A die is rolled. What is the probability of getting 5?
- A. 16.67%
- B. 20%
- C. 50%
- D. 83.33%
Correct Answer: A
Rationale: The correct answer is A: 16.67%. When rolling a standard 6-sided die, each face has an equal probability of 1/6. Therefore, the probability of rolling a 5 specifically is 1/6, which is approximately 16.67% when converted to a percentage. Choices B, C, and D are incorrect because they do not reflect the correct probability of rolling a 5 on a standard die.
If there are 128 ounces in 1 gallon, how many ounces are in 2.5 gallons?
- A. 256 ounces
- B. 320 ounces
- C. 400 ounces
- D. 250 ounces
Correct Answer: B
Rationale: To find the total number of ounces in 2.5 gallons, multiply the number of gallons by the number of ounces per gallon: 2.5 gallons 128 ounces/gallon = 320 ounces. The correct answer is 320 ounces. Choice C (400 ounces) is incorrect because multiplying 2.5 by 128 gives 320, not 400. Choice D (250 ounces) is also incorrect as it seems to be a miscalculation.