Olivia currently earns $51,200 in her job. If her salary increases by 4% this year, what will her new salary be?

Correct Answer: D

Rationale: To find Olivia's new salary after a 4% increase, we calculate 4% of $51,200, which is 0.04 x $51,200 = $2,048. Adding this increase to Olivia's current salary gives us the new salary: $51,200 + $2,048 = $53,248. Therefore, Olivia's salary after the 4% increase will be $53,248. Choices A, B, and C are incorrect as they do not reflect the correct calculation for the new salary after a 4% increase.

Correct Answer: B

Rationale: In this question, the correct answer is B) 2.5ml. To find the equivalent dosage in milliliters for 1/2 teaspoon, we need to know that 1 teaspoon is equal to 5ml. Therefore, if 1 teaspoon is 5ml, then half a teaspoon (1/2) would be half of 5ml, which equals 2.5ml. Option A) 1.25ml is incorrect because it is half of the correct answer, which means it represents a quarter teaspoon, not half. Option C) 3.75ml is incorrect because it is one and a half times the correct answer, which does not align with the concept of halving a teaspoon. Option D) 5ml is incorrect because it represents a full teaspoon, not half a teaspoon as mentioned in the question. Educationally, this question assesses the test taker's understanding of converting between different units of measurement (teaspoons to milliliters) and their ability to perform basic arithmetic operations (division by 2 in this case). It reinforces the importance of being able to convert units accurately, a skill essential in various fields including healthcare where medication dosages must be precise.

Correct Answer: B

Rationale: In this question from the HESI A2 Math Practice Test, the correct answer is B) 2.1ml. To calculate the amount of pure alcohol present in 5ml of hand sanitizer containing 70% alcohol, we multiply the volume of sanitizer by the percentage of alcohol it contains. So, 5ml * 0.70 = 3.5ml of pure alcohol. Therefore, the correct answer is 2.1ml because that is the amount of pure alcohol present in 5ml of the hand sanitizer. Now, let's analyze why the other options are incorrect: A) 1.4ml: This is incorrect because it does not account for the 70% alcohol content in the sanitizer. C) 2.8ml: This is incorrect as it is the result of multiplying 5ml by 0.56 (70% expressed as a decimal), not the correct 0.70. D) 3.5ml: This is incorrect because 3.5ml is the total volume of the hand sanitizer, not the amount of pure alcohol present. This question assesses students' understanding of calculating percentages and applying this knowledge to real-world scenarios. Understanding how to calculate the amount of a specific component in a mixture is crucial for fields like healthcare where accurate measurements are essential. Mastering such problems can help students in medication dosage calculations and other practical applications requiring precise calculations.

Correct Answer: C

Rationale: To find the perimeter of a rectangle, you add the lengths of all sides. The formula for the perimeter of a rectangle is 2 * (length + width). In this case, the length is 15cm and the width is 20cm. Therefore, the perimeter = 2 * (15cm + 20cm) = 65cm. Choice A (30cm), Choice B (55cm), and Choice D (75cm) are incorrect as they do not correctly calculate the perimeter of the given rectangle.

Correct Answer: B

Rationale: To find the total surface area of a sphere, you can use the formula: 4 * π * (radius)^2, where the radius is half the diameter. Given that the diameter is 25cm, the radius is half of that, which is 12.5cm. Substitute this value into the formula: 4 * π * (12.5cm)^2 ≈ 1963 sq cm. Therefore, the total surface area of the decorative globe is approximately 1963 sq cm. Choices A, C, and D are incorrect as they do not correspond to the correct calculation.