What is the result of (6.4)(2.8) · 0.4? Which of the following is correct?
- A. 16.62
- B. 17.92
- C. 41.55
- D. 44.8
Correct Answer: D
Rationale: To simplify the expression, first multiply 6.4 by 2.8 to get 17.92. Then, divide the result by 0.4 to find the final answer. Therefore, (6.4)(2.8) · 0.4 equals 44.8. Choices A, B, and C are incorrect because they do not represent the correct result of the given expression.
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A dry cleaner charges $3 per shirt, $6 per pair of pants, and an extra $5 per item for mending. Annie drops off 5 shirts and 4 pairs of pants, 2 of which need mending. Assuming the cleaner charges an 8% sales tax, what will be the amount of Annie's total bill?
- A. $45.08
- B. $49.00
- C. $52.92
- D. $88.20
Correct Answer: C
Rationale: To determine the total cost before tax, calculate: 5 shirts $3/shirt + 4 pants $6/pair of pants + 2 items mended $5/item mended = $49. Now, multiply this amount by 1.08 to include the 8% sales tax: $49 1.08 = $52.92. Therefore, Annie's total bill will be $52.92. Choice A, $45.08, is incorrect as it does not include the correct calculation for the total bill. Choice B, $49.00, is wrong because it is the total cost before tax and does not consider the added sales tax. Choice D, $88.20, is incorrect as it does not accurately calculate the total bill including the sales tax.
Which of the following is equivalent to 8 pounds and 8 ounces? (Round to the nearest tenth of a kilogram.)
- A. 3.6 kilograms
- B. 3.9 kilograms
- C. 17.6 kilograms
- D. 18.7 kilograms
Correct Answer: B
Rationale: To convert 8 pounds and 8 ounces to kilograms, first convert 8 ounces to pounds by dividing by 16 (since 1 pound = 16 ounces): 8 ounces / 16 = 0.5 pounds. Then add this to the original 8 pounds: 8 pounds + 0.5 pounds = 8.5 pounds. To convert pounds to kilograms, use the conversion factor 1 pound = 0.453592 kilograms. Therefore, 8.5 pounds 0.453592 kg = 3.855 kilograms, which rounds to 3.9 kilograms. Choice A (3.6 kilograms), Choice C (17.6 kilograms), and Choice D (18.7 kilograms) are incorrect conversions or have errors in calculation compared to the correct conversion of 3.9 kilograms.
x · 7 = x − 36. Solve the equation. Which of the following is correct?
- A. x = 6
- B. x = 42
- C. x = 4
- D. x = 252
Correct Answer: B
Rationale: To solve the equation x · 7 = x − 36, start by multiplying both sides by 7 to get 7(x · 7) = 7(x − 36), which simplifies to x = 7x − 252. Next, subtract 7x from both sides to get -6x = -252. Finally, divide both sides by -6 to solve for x, which results in x = 42. Therefore, the correct answer is x = 42. Choice A (x = 6), Choice C (x = 4), and Choice D (x = 252) are incorrect as they do not align with the correct solution derived from the equation.
Simplify the expression. Which of the following is correct? (3/2)(8/3) · (5/4)
- A. 1
- B. 2
- C. 3
- D. 4
Correct Answer: B
Rationale: Using PEMDAS (Parentheses, Exponents, Multiplication and Division, Addition and Subtraction): (3/2)(8/3) · (5/4) = (24/6) · (5/4) = (4/1) · (5/4). To divide fractions, the second fraction is flipped and then multiplied by the first fraction, resulting in (4/1)(4/5) = (16/5), which simplifies to 3(1/5) or 2.
Solve the equation 8x − 6 = 3x + 24. Which of the following is the correct solution?
- A. x = 2.5
- B. x = 3.6
- C. x = 5
- D. x = 6
Correct Answer: D
Rationale: To solve the equation 8x − 6 = 3x + 24, start by adding 6 to both sides: 8x − 6 + 6 = 3x + 24 + 6, which simplifies to 8x = 3x + 30. Next, subtract 3x from both sides to get 5x = 30. Finally, divide both sides by 5 to solve for x: x = 6. Therefore, the correct solution is x = 6. Choices A, B, and C are incorrect because they do not result from the correct algebraic manipulation of the equation.