Nokea
4 − 1/(22) + 24 · (8 + 12). Simplify the expression. Which of the following is correct?
- A. 1.39
- B. 2.74
- C. 4.95
- D. 15.28
Correct Answer: C
Rationale: First, complete the operations in parentheses: 4 − (1/22) + 24 · 20. Next, simplify the exponents: 4 − (1/22) + 24 · 20 = 4 − (1/4) + 24 · 20. Then, complete multiplication and division operations: 4 − (1/4) + 24 · 20 = 4 − 0.25 + 1.2. Finally, complete addition and subtraction operations: 4 − 0.25 + 1.2 = 4.95. Choice A, 1.39, is incorrect as it does not match the correct calculation. Choice B, 2.74, is incorrect as it is not the result of the given expression. Choice D, 15.28, is incorrect as it is not the correct simplification of the initial expression.
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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.
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.
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 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.
Which statement about the following set is true? {60, 5, 18, 20, 37, 37, 11, 90, 72}
- A. The median and the mean are equal.
- B. The mean is less than the mode.
- C. The mode is greater than the median.
- D. The median is less than the mean.
Correct Answer: D
Rationale: To find the median, we first need to arrange the set in ascending order: {5, 11, 18, 20, 37, 37, 60, 72, 90}. The median is the middle value, which is 37 in this case. The mean is calculated by adding all numbers and dividing by the total count, which gives a mean greater than 37. Therefore, the statement that the median is less than the mean is correct. Choice A is incorrect because the median and mean are not equal in this set. Choice B is incorrect as the mean is greater than the mode in this set. Choice C is incorrect as the mode is 37, which is equal to the median, not greater.