Nursing Elites

1. Which element is used in fire extinguishers to smother flames by displacing oxygen?

• A. Nitrogen
• B. Carbon dioxide
• C. Helium
• D. Argon

Correct answer: B

Rationale: Carbon dioxide is the correct answer. It is used in fire extinguishers because it displaces oxygen, which is necessary for combustion. When carbon dioxide is released onto a fire, it reduces the oxygen concentration around the flames, effectively smothering the fire. This disruption of oxygen availability interrupts the chemical reaction that sustains the fire. Nitrogen (Choice A), helium (Choice C), and argon (Choice D) are not typically used in fire extinguishers for smothering flames by displacing oxygen. Nitrogen is an inert gas that can displace oxygen but is not as effective as carbon dioxide in fire suppression.

2. Mandy can buy 4 containers of yogurt and 3 boxes of crackers for $9.55. She can buy 2 containers of yogurt and 2 boxes of crackers for $5.90. How much does one box of crackers cost?

• A. $1.75
• B. $2.00
• C. $2.25
• D. $2.50

Correct answer: C

Rationale: To solve this problem, we can set up a system of equations. Let the cost of one container of yogurt be y and the cost of one box of crackers be c. From the first scenario, we have 4y + 3c = 9.55. From the second scenario, we have 2y + 2c = 5.90. Solving these equations simultaneously, we find that c = $2.25. Therefore, one box of crackers costs $2.25. Choice A, $1.75, is incorrect because it does not satisfy the given conditions in the system of equations. Choice B, $2.00, is incorrect as it does not match the calculated solution. Choice D, $2.50, is incorrect as it does not align with the calculated value for one box of crackers.

3. What is the main argument presented in the passage?

• A. The custom of tipping should be abolished in favor of paying servers a living wage
• B. Tipping enhances service quality in restaurants
• C. Servers' pay should be determined by their performance
• D. Customers derive pleasure from the custom of tipping

Correct answer: A

Rationale: The correct answer is A: 'The custom of tipping should be abolished in favor of paying servers a living wage.' The rationale is that the passage argues for eliminating tipping and ensuring servers receive a fair wage. This is supported by the idea that servers should be paid adequately rather than relying on tips. Choice B is incorrect because the passage does not support the idea that tipping enhances service quality; it argues for a living wage instead. Choice C is incorrect as there is no mention of paying servers based on performance in the passage. Choice D is incorrect as the passage does not focus on customers' enjoyment of tipping but rather on the need to abolish the practice for fairer wages.

4. Which of the following is a unit of power?

• A. Newton-meter (N·m)
• B. Joule (J)
• C. Watt (W)
• D. Kilogram (kg)

Correct answer: C

Rationale: The correct answer is C: Watt (W). Power is the rate at which work is done or energy is transferred. The unit of power is the watt (W), named after James Watt, the inventor of the steam engine. A Newton-meter (N·m) is a unit of torque, Joule (J) is a unit of energy, and Kilogram (kg) is a unit of mass, not power. Therefore, choices A, B, and D are incorrect as they represent units of torque, energy, and mass, respectively, and not power.

5. How does the respiratory system facilitate gas exchange between air and blood?

• A. Diffusion
• B. Exhalation
• C. Inspiration
• D. Ventilation

Correct answer: A

Rationale: The correct answer is 'Diffusion.' Diffusion is the process by which gases are exchanged between air in the alveoli and blood in the capillaries. Oxygen moves from the alveoli into the blood, while carbon dioxide moves from the blood into the alveoli through diffusion. Exhalation is the process of expelling air from the lungs, inspiration is the process of inhaling air into the lungs, and ventilation refers to the overall movement of air in and out of the lungs. While these processes are essential for the respiratory system to function, they are not directly responsible for the gas exchange between air and blood, which is primarily achieved through diffusion.

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