What is the area of a triangle with a base of 10 cm and a height of 7 cm?
- A. 70 cm²
- B. 35 cm²
- C. 140 cm²
- D. 100 cm²
Correct Answer: B
Rationale: To find the area of a triangle, you use the formula A = 1/2 base height. Substituting the given values: A = 1/2 10 cm 7 cm = 35 cm². Therefore, the correct answer is B. Choice A (70 cm²) is incorrect as it seems to be the product of the base and height rather than the area formula. Choice C (140 cm²) is incorrect as it appears to be twice the correct answer, possibly a result of a miscalculation. Choice D (100 cm²) is incorrect as it does not reflect the correct calculation based on the given base and height values.
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Which of the following is the y-intercept of the line whose equation is 7y − 42x + 7 = 0?
- A. (1/6, 0)
- B. (6, 0)
- C. (0, −1)
- D. (−1, 0)
Correct Answer: C
Rationale: To find the y-intercept, set x = 0 in the equation 7y − 42x + 7 = 0. This simplifies to 7y - 42(0) + 7 = 0, which gives 7y = -7. Solving for y, we get y = -1. Therefore, the y-intercept is where x = 0, so the correct answer is (0, -1).
Choice A (1/6, 0) is incorrect as it does not satisfy the given equation when x = 0. Choice B (6, 0) is incorrect as it represents the x-intercept. Choice D (-1, 0) is incorrect as it does not correspond to the y-intercept of the given equation.
A sandwich shop earns $4 for every sandwich (s) it sells, $2 for every drink (d), and $1 for every cookie (c). If this is all the shop sells, which of the following equations represents what the shop's revenue (r) is over three days?
- A. r = 4s + 2d + 1c
- B. r = 8s + 4d + 2c
- C. r = 12s + 6d + 3c
- D. r = 16s + 8d + 4c
Correct Answer: A
Rationale: Let s be the number of sandwiches sold. Each sandwich earns $4, so selling s sandwiches at $4 each results in revenue of $4s. Similarly, d drinks at $2 each give $2d of income, and cookies bring in $1c. Summing these values gives total revenue = 4s + 2d + 1c. Therefore, option A, r = 4s + 2d + 1c, correctly represents the shop's revenue. Choices B, C, and D are incorrect because they incorrectly multiply the prices of each item by more than one day's sales, which would overstate the total revenue for a three-day period.
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.
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.
A student gets 42 questions out of 48 correct on a quiz. What is the percentage of questions that the student answered correctly?
- A. 1.14%
- B. 82.50%
- C. 85.00%
- D. 87.50%
Correct Answer: D
Rationale: To find the percentage of questions answered correctly, divide the number of correct questions by the total number of questions: 42/48 = 0.875. Multiply the result by 100 to express it as a percentage, which gives 87.5%. Therefore, the correct answer is 87.50%. Choice A (1.14%) is incorrect as it does not reflect the correct percentage. Choices B (82.50%) and C (85.00%) are also incorrect as they do not align with the calculation based on the given information.