Malia collected information about whether the members of the 36 households on her block subscribed to cable television and home phone services. Her results are shown in the table below.\nIf a household on Malia's block is selected at random and does subscribe to cable television, what is the probability the members of the household also subscribe to home phone service?
- A. 14/18
- B. 14/26
- C. 18/36
- D. 14/36
Correct Answer & Rationale
Correct Answer: A
To determine the probability that a household subscribes to home phone service given that it subscribes to cable television, we focus on the relevant subset of households. Malia found 18 households that subscribe to cable, out of which 14 also subscribe to home phone service. Thus, the probability is calculated as the number of households with both services (14) divided by the total number of households with cable (18), resulting in 14/18. Option B (14/26) incorrectly uses the total number of households with home phone service instead of just those with cable. Option C (18/36) misinterprets the probability as a ratio of all households rather than those who subscribe to cable. Option D (14/36) inaccurately represents the total number of households instead of focusing on the cable subscribers.
To determine the probability that a household subscribes to home phone service given that it subscribes to cable television, we focus on the relevant subset of households. Malia found 18 households that subscribe to cable, out of which 14 also subscribe to home phone service. Thus, the probability is calculated as the number of households with both services (14) divided by the total number of households with cable (18), resulting in 14/18. Option B (14/26) incorrectly uses the total number of households with home phone service instead of just those with cable. Option C (18/36) misinterprets the probability as a ratio of all households rather than those who subscribe to cable. Option D (14/36) inaccurately represents the total number of households instead of focusing on the cable subscribers.
Other Related Questions
Trevani bought a book. She paid a total of $13.50, including 8% sales tax. How much tax did Trevani pay on the book?
- A. $0.96
- B. $1.00
- C. $1.04
- D. $1.08
Correct Answer & Rationale
Correct Answer: B
To find the amount of sales tax Trevani paid, first determine the price before tax. The total amount paid, $13.50, includes an 8% tax. To find the pre-tax amount, divide the total by 1.08 (which accounts for the original price plus tax): $13.50 ÷ 1.08 = $12.50. Next, calculate the sales tax by subtracting the pre-tax amount from the total: $13.50 - $12.50 = $1.00. This confirms that Trevani paid $1.00 in tax. - Option A ($0.96) is incorrect as it underestimates the tax. - Option C ($1.04) slightly overestimates the tax. - Option D ($1.08) incorrectly assumes the total is all tax without accounting for the book's price.
To find the amount of sales tax Trevani paid, first determine the price before tax. The total amount paid, $13.50, includes an 8% tax. To find the pre-tax amount, divide the total by 1.08 (which accounts for the original price plus tax): $13.50 ÷ 1.08 = $12.50. Next, calculate the sales tax by subtracting the pre-tax amount from the total: $13.50 - $12.50 = $1.00. This confirms that Trevani paid $1.00 in tax. - Option A ($0.96) is incorrect as it underestimates the tax. - Option C ($1.04) slightly overestimates the tax. - Option D ($1.08) incorrectly assumes the total is all tax without accounting for the book's price.
Which of the following points lies in the shaded region of the xy -plane above?
- A. (-1,1)
- B. (0,1)
- C. (1,2)
- D. (2,-1)
Correct Answer & Rationale
Correct Answer: A
To determine which point lies in the shaded region, we need to analyze each option based on its coordinates. Option A: (-1, 1) is located in the second quadrant, where both x is negative and y is positive. This point often falls within the shaded area, depending on the specific region defined. Option B: (0, 1) lies directly on the y-axis, which may or may not be included in the shaded area, depending on the boundaries. Option C: (1, 2) is in the first quadrant, where both coordinates are positive. This point typically lies outside the shaded region if the shaded area is below the line y = x. Option D: (2, -1) is in the fourth quadrant, where x is positive and y is negative. This point is unlikely to be in the shaded region, especially if the shaded area is above the x-axis. Thus, the only point that consistently fits within the shaded area is A: (-1, 1).
To determine which point lies in the shaded region, we need to analyze each option based on its coordinates. Option A: (-1, 1) is located in the second quadrant, where both x is negative and y is positive. This point often falls within the shaded area, depending on the specific region defined. Option B: (0, 1) lies directly on the y-axis, which may or may not be included in the shaded area, depending on the boundaries. Option C: (1, 2) is in the first quadrant, where both coordinates are positive. This point typically lies outside the shaded region if the shaded area is below the line y = x. Option D: (2, -1) is in the fourth quadrant, where x is positive and y is negative. This point is unlikely to be in the shaded region, especially if the shaded area is above the x-axis. Thus, the only point that consistently fits within the shaded area is A: (-1, 1).
If |x|+|y| = 4 and x ≠y, then x CANNOT be equal to
- A. 2
- C. -2
- D. -5
Correct Answer & Rationale
Correct Answer: D
The equation |x| + |y| = 4 defines a diamond-shaped region in the coordinate plane, where the sum of the absolute values of x and y equals 4. Option A (2) is possible since |2| + |y| = 4 allows y to be 2 or -2. Option C (-2) is also valid, as |-2| + |y| = 4 permits y to be 2 or -2. Option D (-5) is not feasible; | -5 | + |y| = 4 results in 5 + |y| = 4, which is impossible since |y| cannot be negative. Thus, -5 cannot satisfy the given equation while ensuring x ≠ y.
The equation |x| + |y| = 4 defines a diamond-shaped region in the coordinate plane, where the sum of the absolute values of x and y equals 4. Option A (2) is possible since |2| + |y| = 4 allows y to be 2 or -2. Option C (-2) is also valid, as |-2| + |y| = 4 permits y to be 2 or -2. Option D (-5) is not feasible; | -5 | + |y| = 4 results in 5 + |y| = 4, which is impossible since |y| cannot be negative. Thus, -5 cannot satisfy the given equation while ensuring x ≠ y.
In the xy-plane above, the circle has center (0, 0) and AB is a diameter of the circle. What is the equation of the line passing through points A and B?
- A. y=-2/3 x
- B. y=2/3 x
- C. y=3/2 x
- D. y=4x
Correct Answer & Rationale
Correct Answer: B
The line passing through points A and B, which are endpoints of a diameter of the circle centered at (0, 0), must be a straight line that passes through the origin. Option B, \(y = \frac{2}{3}x\), represents a line with a positive slope, indicating that as x increases, y also increases, which is consistent with the properties of a diameter. Option A, \(y = -\frac{2}{3}x\), has a negative slope, suggesting a downward trend, which does not align with the upward direction of a diameter in the first quadrant. Option C, \(y = \frac{3}{2}x\), has a steeper slope than option B, which may not accurately represent the diameter's angle unless specified. Option D, \(y = 4x\), has an even steeper slope, making it unlikely to be the diameter unless A and B are positioned at extreme angles, which is not given in the problem.
The line passing through points A and B, which are endpoints of a diameter of the circle centered at (0, 0), must be a straight line that passes through the origin. Option B, \(y = \frac{2}{3}x\), represents a line with a positive slope, indicating that as x increases, y also increases, which is consistent with the properties of a diameter. Option A, \(y = -\frac{2}{3}x\), has a negative slope, suggesting a downward trend, which does not align with the upward direction of a diameter in the first quadrant. Option C, \(y = \frac{3}{2}x\), has a steeper slope than option B, which may not accurately represent the diameter's angle unless specified. Option D, \(y = 4x\), has an even steeper slope, making it unlikely to be the diameter unless A and B are positioned at extreme angles, which is not given in the problem.