Quickly multiply 24x16?
- A. 20x20-4x4
- B. 20x20
- C. 20x10+4x6
- D. 25x10+4x15
Correct Answer & Rationale
Correct Answer: A
Option A, 20x20 - 4x4, effectively utilizes the difference of squares method. It simplifies the multiplication by recognizing that 24 can be expressed as 20 + 4 and 16 as 20 - 4, leading to a calculation of (20+4)(20-4). Option B, 20x20, underestimates the value of 24 and 16, yielding only 400 instead of the correct 384. Option C, 20x10 + 4x6, inaccurately breaks down the multiplication, leading to 200 + 24, which totals 224. Option D, 25x10 + 4x15, misrepresents the factors, resulting in 250 + 60, totaling 310. Thus, option A is the most accurate approach for this multiplication.
Option A, 20x20 - 4x4, effectively utilizes the difference of squares method. It simplifies the multiplication by recognizing that 24 can be expressed as 20 + 4 and 16 as 20 - 4, leading to a calculation of (20+4)(20-4). Option B, 20x20, underestimates the value of 24 and 16, yielding only 400 instead of the correct 384. Option C, 20x10 + 4x6, inaccurately breaks down the multiplication, leading to 200 + 24, which totals 224. Option D, 25x10 + 4x15, misrepresents the factors, resulting in 250 + 60, totaling 310. Thus, option A is the most accurate approach for this multiplication.
Other Related Questions
Shaded region shows?
- A. 3/4 x 1/2
- B. 3/4 x 3/4
- C. 3/4 x 3/2
- D. 3/4 x 3
Correct Answer & Rationale
Correct Answer: A
The shaded region represents the area of a rectangle formed by multiplying two fractions. Option A, \( \frac{3}{4} \times \frac{1}{2} \), correctly calculates the area of a rectangle with a length of \( \frac{3}{4} \) and a width of \( \frac{1}{2} \), resulting in \( \frac{3}{8} \). Option B, \( \frac{3}{4} \times \frac{3}{4} \), represents a larger area, \( \frac{9}{16} \), which does not match the shaded region. Option C, \( \frac{3}{4} \times \frac{3}{2} \), yields \( \frac{9}{8} \), exceeding the shaded area. Finally, option D, \( \frac{3}{4} \times 3 \), results in \( \frac{9}{4} \), also too large. Thus, only option A accurately reflects the area of the shaded region.
The shaded region represents the area of a rectangle formed by multiplying two fractions. Option A, \( \frac{3}{4} \times \frac{1}{2} \), correctly calculates the area of a rectangle with a length of \( \frac{3}{4} \) and a width of \( \frac{1}{2} \), resulting in \( \frac{3}{8} \). Option B, \( \frac{3}{4} \times \frac{3}{4} \), represents a larger area, \( \frac{9}{16} \), which does not match the shaded region. Option C, \( \frac{3}{4} \times \frac{3}{2} \), yields \( \frac{9}{8} \), exceeding the shaded area. Finally, option D, \( \frac{3}{4} \times 3 \), results in \( \frac{9}{4} \), also too large. Thus, only option A accurately reflects the area of the shaded region.
Favorite food via survey numbers. Best measure?
- A. Mean
- B. Median
- C. Mode
- D. Mean+median
Correct Answer & Rationale
Correct Answer: C
When analyzing survey data on favorite foods, the mode is the best measure since it identifies the most frequently chosen option, reflecting the popular preference among respondents. The mean can be skewed by outliers, making it less reliable in this context. The median, while useful for understanding the middle value, does not capture the most popular choice effectively. Combining mean and median (option D) does not address the core goal of identifying the favorite food, which is best represented by the mode. Thus, the mode provides a clear insight into the most favored food item.
When analyzing survey data on favorite foods, the mode is the best measure since it identifies the most frequently chosen option, reflecting the popular preference among respondents. The mean can be skewed by outliers, making it less reliable in this context. The median, while useful for understanding the middle value, does not capture the most popular choice effectively. Combining mean and median (option D) does not address the core goal of identifying the favorite food, which is best represented by the mode. Thus, the mode provides a clear insight into the most favored food item.
Point (-3,-6) quadrant?
- A. I
- B. II
- C. III
- D. IV
Correct Answer & Rationale
Correct Answer: C
The point (-3, -6) is located in the Cartesian coordinate system where the x-coordinate is negative and the y-coordinate is also negative. This combination places the point in Quadrant III, where both x and y values are less than zero. Option A (I) is incorrect as Quadrant I contains positive x and y values. Option B (II) is wrong because Quadrant II has a negative x value and a positive y value. Option D (IV) is not applicable since Quadrant IV features a positive x value and a negative y value. Thus, the only quadrant that matches the coordinates (-3, -6) is Quadrant III.
The point (-3, -6) is located in the Cartesian coordinate system where the x-coordinate is negative and the y-coordinate is also negative. This combination places the point in Quadrant III, where both x and y values are less than zero. Option A (I) is incorrect as Quadrant I contains positive x and y values. Option B (II) is wrong because Quadrant II has a negative x value and a positive y value. Option D (IV) is not applicable since Quadrant IV features a positive x value and a negative y value. Thus, the only quadrant that matches the coordinates (-3, -6) is Quadrant III.
Equivalent to 2(4f+2g)? Select ALL.
- A. 4*(2f+g)
- B. 4(2f+2g)
- C. 2f(4+2g)
- D. 16f+4g
- E. 8f+2g
Correct Answer & Rationale
Correct Answer: A,F
To determine which expressions are equivalent to \( 2(4f + 2g) \), we first simplify it: \[ 2(4f + 2g) = 8f + 4g \] Now, let's analyze each option: **A: \( 4(2f + g) \)** This expands to \( 8f + 4g \), matching our simplified expression. **B: \( 4(2f + 2g) \)** This simplifies to \( 8f + 8g \), which does not match \( 8f + 4g \). **C: \( 2f(4 + 2g) \)** This expands to \( 8f + 4fg \), introducing an extra term \( 4fg \) that makes it unequal. **D: \( 16f + 4g \)** This expression has \( 16f \), which is double the \( 8f \) we expect, thus it is not equivalent. **E: \( 8f + 2g \)** Here, while \( 8f \) matches, \( 2g \) does not equal \( 4g \), making it non-equivalent. **F: \( 8f + 4g \)** This matches our simplified expression exactly, confirming its equivalence. In summary, options A and F correctly represent the original expression, while B, C, D, and E do not.
To determine which expressions are equivalent to \( 2(4f + 2g) \), we first simplify it: \[ 2(4f + 2g) = 8f + 4g \] Now, let's analyze each option: **A: \( 4(2f + g) \)** This expands to \( 8f + 4g \), matching our simplified expression. **B: \( 4(2f + 2g) \)** This simplifies to \( 8f + 8g \), which does not match \( 8f + 4g \). **C: \( 2f(4 + 2g) \)** This expands to \( 8f + 4fg \), introducing an extra term \( 4fg \) that makes it unequal. **D: \( 16f + 4g \)** This expression has \( 16f \), which is double the \( 8f \) we expect, thus it is not equivalent. **E: \( 8f + 2g \)** Here, while \( 8f \) matches, \( 2g \) does not equal \( 4g \), making it non-equivalent. **F: \( 8f + 4g \)** This matches our simplified expression exactly, confirming its equivalence. In summary, options A and F correctly represent the original expression, while B, C, D, and E do not.