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What is the perimeter of a rectangle with a length of 12 cm and a width of 5 cm?
- A. 17 cm
- B. 24 cm
- C. 34 cm
- D. 40 cm
Correct Answer: C
Rationale: The correct formula for the perimeter of a rectangle is P = 2(l + w), where l represents the length and w represents the width. Substituting the given values into the formula: P = 2(12 cm + 5 cm) = 2(17 cm) = 34 cm. Therefore, the perimeter of the rectangle is 34 cm. Choice A (17 cm) is incorrect as it seems to have added only the length and width without multiplying by 2. Choice B (24 cm) is incorrect as it does not consider the multiplication by 2. Choice D (40 cm) is incorrect as it seems to have added the length and width without multiplying by 2.
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What is the result of the expression 102 - 7(3 - 4) - 25? Which of the following is correct?
- A. -12
- B. 2
- C. 68
- D. 82
Correct Answer: D
Rationale: To simplify the expression, we follow the order of operations (PEMDAS): Parentheses, Exponents, Multiplication and Division (from left to right), Addition and Subtraction (from left to right). First, solve inside the parentheses: 3 - 4 = -1. Then, multiply -1 by 7: -1 * 7 = -7. Now, substitute these values back into the expression: 102 - (-7) - 25 = 102 + 7 - 25 = 109 - 25 = 84. Therefore, the correct answer is 84. Choices A, B, and C are incorrect as they do not represent the correct simplification of the given expression.
If the price of a shirt was originally $30 and it is now being sold at a 20% discount, what is the sale price of the shirt?
- A. $24
- B. $25
- C. $26
- D. $28
Correct Answer: A
Rationale: To find the discount amount, calculate 20% of $30: 0.20 $30 = $6. Subtract the discount from the original price to get the sale price: $30 - $6 = $24. Therefore, the correct answer is $24. Choices B, C, and D are incorrect as they do not reflect the correct calculation of applying a 20% discount to the original price of $30.
Melissa is ordering fencing to enclose a square area of 5625 square feet. How many feet of fencing does she need?
- A. 75 feet
- B. 150 feet
- C. 300 feet
- D. 5,625 feet
Correct Answer: C
Rationale: To find the side length of the square, we take the square root of the area: √5625 ft² = 75 ft. The perimeter of a square is 4 times its side length, so the fencing needed is 4 75 ft = 300 ft. Therefore, Melissa needs 300 feet of fencing to enclose the square area of 5625 square feet. Option A (75 feet) is the side length of the square, not the fencing needed. Option B (150 feet) is half of the correct answer and does not account for all sides of the square. Option D (5,625 feet) is the total area, not the length of fencing required.
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.
The owner of a newspaper has noticed that print subscriptions have gone down 40% while online subscriptions have gone up 60%. Print subscriptions once accounted for 70% of the newspaper's business, and online subscriptions accounted for 25%. What is the overall percentage growth or decline in business?
- A. 13% decline
- B. 15% decline
- C. 28% growth
- D. 8% growth
Correct Answer: A
Rationale: To calculate the decline in business, start with the 40% decline in the 70% share of print subscriptions: 40% of 70% = 0.40 0.70 = 0.28 = 28% decline. Next, calculate the growth from the 60% increase in the 25% share of online subscriptions: 60% of 25% = 0.60 0.25 = 0.15 = 15% growth. To find the overall change, sum the decline and growth percentages: 28% decline + 15% growth = -0.28 + 0.15 = -0.13 = 13% decline. Therefore, the overall percentage change in the newspaper's business is a 13% decline. Option A is the correct answer. Option B is incorrect because it doesn't consider the correct calculations for both the decline and growth. Option C is incorrect as it misinterprets the net change in business. Option D is incorrect as it miscalculates the overall percentage growth or decline.