6[4 + 2(1 - 3)] =
- B. 20
- C. 24
- D. 48
Correct Answer & Rationale
Correct Answer: A
To solve the expression 6[4 + 2(1 - 3)], begin by simplifying inside the brackets. The calculation within the parentheses, 1 - 3, equals -2. Next, multiply by 2 to get -4. Now, the expression inside the brackets is 4 - 4, which simplifies to 0. Finally, multiplying 6 by 0 results in 0. Option B (20), C (24), and D (48) arise from miscalculations, such as incorrectly handling the order of operations or not simplifying the expression fully. None of these options account for the zero outcome from the calculations.
To solve the expression 6[4 + 2(1 - 3)], begin by simplifying inside the brackets. The calculation within the parentheses, 1 - 3, equals -2. Next, multiply by 2 to get -4. Now, the expression inside the brackets is 4 - 4, which simplifies to 0. Finally, multiplying 6 by 0 results in 0. Option B (20), C (24), and D (48) arise from miscalculations, such as incorrectly handling the order of operations or not simplifying the expression fully. None of these options account for the zero outcome from the calculations.
Other Related Questions
The fraction x/24 is equal to 0.75. What is the value of x?
- A. 3
- B. 6
- C. 9
- D. 18
Correct Answer & Rationale
Correct Answer: D
To find the value of x in the equation x/24 = 0.75, we start by converting 0.75 to a fraction, which is 75/100 or 3/4. Setting the two fractions equal gives us x/24 = 3/4. Cross-multiplying leads to 4x = 72. Dividing both sides by 4 results in x = 18. Option A (3) is too low; substituting it back yields 3/24 = 0.125. Option B (6) also falls short, as 6/24 = 0.25. Option C (9) gives 9/24 = 0.375, still incorrect. Only option D (18) satisfies the original equation, confirming its validity.
To find the value of x in the equation x/24 = 0.75, we start by converting 0.75 to a fraction, which is 75/100 or 3/4. Setting the two fractions equal gives us x/24 = 3/4. Cross-multiplying leads to 4x = 72. Dividing both sides by 4 results in x = 18. Option A (3) is too low; substituting it back yields 3/24 = 0.125. Option B (6) also falls short, as 6/24 = 0.25. Option C (9) gives 9/24 = 0.375, still incorrect. Only option D (18) satisfies the original equation, confirming its validity.
Frederica used 13.4 gallons of gasoline to drive 448.9 miles. What was the average number of miles she drove per gallon of gasoline?
- A. 3.4 mpg
- B. 33.5 mpg
- C. 60.15 mpg
- D. 435.5 mpg
Correct Answer & Rationale
Correct Answer: B
To find the average miles per gallon (mpg), divide the total miles driven by the gallons used. Here, 448.9 miles divided by 13.4 gallons equals approximately 33.5 mpg. Option A (3.4 mpg) is incorrect as it significantly underestimates the fuel efficiency. Option C (60.15 mpg) overestimates the efficiency, suggesting an unrealistic performance for a typical vehicle. Option D (435.5 mpg) is also incorrect, as it implies an implausibly high efficiency that is not achievable with conventional vehicles. Thus, the calculation confirms that 33.5 mpg accurately represents Frederica's fuel efficiency.
To find the average miles per gallon (mpg), divide the total miles driven by the gallons used. Here, 448.9 miles divided by 13.4 gallons equals approximately 33.5 mpg. Option A (3.4 mpg) is incorrect as it significantly underestimates the fuel efficiency. Option C (60.15 mpg) overestimates the efficiency, suggesting an unrealistic performance for a typical vehicle. Option D (435.5 mpg) is also incorrect, as it implies an implausibly high efficiency that is not achievable with conventional vehicles. Thus, the calculation confirms that 33.5 mpg accurately represents Frederica's fuel efficiency.
A record store sold 100 copies of a CD in January. In February, the store's sales of the CD increased by 10 percent over the January sales. In March, the store sold 20 percent more copies of the CD than it sold in February. How many copies of the CD did the store sell in March?
- A. 120
- B. 122
- C. 130
- D. 132
Correct Answer & Rationale
Correct Answer: D
To find the number of CDs sold in March, start with January's sales of 100 copies. February's sales increased by 10%, resulting in 100 + (10% of 100) = 110 copies sold. In March, the store sold 20% more than February's sales: 110 + (20% of 110) = 110 + 22 = 132 copies. Option A (120) incorrectly assumes a lower percentage increase in February. Option B (122) miscalculates the increase in March. Option C (130) underestimates the sales for March by not applying the correct percentage increase. Thus, the accurate calculation leads to 132 copies sold in March.
To find the number of CDs sold in March, start with January's sales of 100 copies. February's sales increased by 10%, resulting in 100 + (10% of 100) = 110 copies sold. In March, the store sold 20% more than February's sales: 110 + (20% of 110) = 110 + 22 = 132 copies. Option A (120) incorrectly assumes a lower percentage increase in February. Option B (122) miscalculates the increase in March. Option C (130) underestimates the sales for March by not applying the correct percentage increase. Thus, the accurate calculation leads to 132 copies sold in March.
1 is 3 percent of what number?
- A. 1/3
- B. 3
- C. 30
- D. 33,1/3
Correct Answer & Rationale
Correct Answer: D
To find the number of which 1 is 3 percent, we set up the equation: 1 = 0.03 * x. Solving for x gives x = 1 / 0.03, which equals 33.33 (or 33 1/3). Option A (1/3) is incorrect as it represents a much smaller value, specifically 0.33. Option B (3) misinterprets the percentage, suggesting that 1 is 33.33% of 3, which is not accurate. Option C (30) also fails, as 3% of 30 is 0.9, not 1. Thus, only option D correctly identifies the number as 33 1/3.
To find the number of which 1 is 3 percent, we set up the equation: 1 = 0.03 * x. Solving for x gives x = 1 / 0.03, which equals 33.33 (or 33 1/3). Option A (1/3) is incorrect as it represents a much smaller value, specifically 0.33. Option B (3) misinterprets the percentage, suggesting that 1 is 33.33% of 3, which is not accurate. Option C (30) also fails, as 3% of 30 is 0.9, not 1. Thus, only option D correctly identifies the number as 33 1/3.