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Evaluate the following expression: -x + y + xy, when x = 4 and y = 2.
- A. 2
- B. 6
- C. 12
- D. 8
Correct Answer: B
Rationale: To evaluate the expression, substitute x = 4 and y = 2 into the expression: -4 + 2 + 4*2. Calculate each term: -4 + 2 = -2, then 4*2 = 8. Adding these results gives -2 + 8 = 6. Therefore, the correct answer is 6. Choice A (2) is incorrect as it does not consider all terms in the expression. Choice C (12) is incorrect as it miscalculates the result by failing to account for the negative sign. Choice D (8) is incorrect as it doesn't consider the negative value of the first term in the expression.
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What is the ratio of women to the total number of students in the class?
- A. 4:7
- B. 16:28
- C. 3:5
- D. 2:3
Correct Answer: A
Rationale: To find the ratio of women to the total number of students, you need to simplify the ratio of 16:28. By dividing both numbers by the greatest common factor, which is 4, you get 4:7. Therefore, the correct ratio of women to the total number of students is 4:7. Choice A is correct. Choices C and D are incorrect because they do not represent a valid ratio. Choice B is the original ratio given in the question, which should be simplified to 4:7 as explained in the rationale.
A baseball team won 72 games. This was 90% of the games it played. How many games did it play?
- A. 75
- B. 80
- C. 85
- D. 100
Correct Answer: B
Rationale: Let the total number of games be x. If the team won 72 games, which is 90% of the total games played, we can set up the equation: 72 = 0.90 * x. To find x, divide 72 by 0.90: x = 72 / 0.90 = 80 games. Therefore, the baseball team played 80 games in total. Choice A, 75, is incorrect because it is less than 80. Choice C, 85, is incorrect as it is more than 80. Choice D, 100, is incorrect as it is significantly more than the calculated total of 80 games.
How many ounces are in 3 pints?
- A. 24 ounces
- B. 48 ounces
- C. 32 ounces
- D. 64 ounces
Correct Answer: B
Rationale: To find out how many ounces are in 3 pints, you need to multiply the number of pints by the number of ounces in 1 pint. Since there are 16 ounces in 1 pint, 3 pints equal 3 * 16 = 48 ounces. Therefore, the correct answer is 48 ounces. Choice A (24 ounces) is incorrect because it miscalculates the conversion. Choice C (32 ounces) is incorrect as it does not correctly apply the conversion factor. Choice D (64 ounces) is incorrect as it doubles the correct answer, showing a misunderstanding of the conversion.
The physician ordered 3,000 units of heparin; 5,000 U/mL is on hand. How many milliliters will you give?
- A. 0.5 ml
- B. 0.6 ml
- C. 0.75 ml
- D. 0.8 ml
Correct Answer: B
Rationale: To calculate the volume of heparin needed, use the formula: Volume of Heparin = (Ordered Units / Concentration of Heparin). Substituting the values, Volume = (3,000 units / 5,000 U/mL) = 0.6 ml. Therefore, the correct answer is 0.6 ml. Choice A (0.5 ml) is incorrect as it results from an incorrect calculation. Choices C (0.75 ml) and D (0.8 ml) are also incorrect calculations based on the wrong formula application or mathematical errors.
How many millimeters are in 5 meters?
- A. 5000 mm
- B. 4000 mm
- C. 5500 mm
- D. 6000 mm
Correct Answer: A
Rationale: To convert meters to millimeters, you multiply by 1000 since there are 1000 millimeters in 1 meter. Therefore, 5 meters multiplied by 1000 equals 5000 millimeters. Choice A is correct as it represents the accurate conversion from meters to millimeters. Choices B, C, and D are incorrect as they do not provide the correct conversion factor from meters to millimeters.