If m represents a car's average mileage in miles per gallon, p represents the price of gas in dollars per gallon, and d represents a distance in miles, which of the following algebraic equations represents the cost, c, of gas per mile?
- A. c = dp/m
- B. c = p/m
- C. c = mp/d
- D. c = m/p
Correct Answer: B
Rationale: The cost of gas per mile, c, is calculated by dividing the price of gas, represented by p, by the car's average mileage, represented by m. Therefore, the correct equation is c = p/m. Choice A (dp/m) incorrectly multiplies the price of gas and distance, while choice C (mp/d) incorrectly multiplies the average mileage and price of gas. Choice D (m/p) incorrectly divides the average mileage by the price of gas, which does not represent the cost of gas per mile.
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Melissa is ordering fencing to enclose a square area of 5625 square feet. How many feet of fencing does she need?
- A. 75 feet
- B. 150 feet
- C. 300 feet
- D. 5,625 feet
Correct Answer: C
Rationale: To find the side length of the square, we take the square root of the area: √5625 ft² = 75 ft. The perimeter of a square is 4 times its side length, so the fencing needed is 4 75 ft = 300 ft. Therefore, Melissa needs 300 feet of fencing to enclose the square area of 5625 square feet. Option A (75 feet) is the side length of the square, not the fencing needed. Option B (150 feet) is half of the correct answer and does not account for all sides of the square. Option D (5,625 feet) is the total area, not the length of fencing required.
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 car dealership's commercials claim that this year's models are 20% off the list price, plus they will pay the first 3 monthly payments. If a car is listed for $26,580, and the monthly payments are set at $250, what is the total potential savings?
- A. $1,282
- B. $5,566
- C. $6,066
- D. $20,514
Correct Answer: C
Rationale: To calculate the total potential savings: First, find the 20% discount on the list price of $26,580: 0.20 $26,580 = $5,316. Then, determine the savings over the first 3 months of payments: 3 months $250/month = $750. Add the discount and the monthly payment savings to get the total potential savings: $5,316 + $750 = $6,066. Therefore, the correct answer is $6,066. Choice A, $1,282, is incorrect because it does not account for the total savings from both the discount and the monthly payments. Choice B, $5,566, is incorrect as it miscalculates the total savings by excluding the savings from the monthly payments. Choice D, $20,514, is incorrect as it does not consider the discount and only focuses on the list price.
Which of the following lists is in order from least to greatest? 2−1 , −(4/3), (−1)3 , (2/5)
- A. 2−1 , −(4/3), (−1)3 , (2/5)
- B. −(4/3), (−1)3 , 2−1 , (2/5)
- C. −(4/3), (2/5), 2−1 , (−1)3
- D. −(4/3), (−1)3 , (2/5), 2−1
Correct Answer: D
Rationale: To determine the correct order from least to greatest, start by simplifying the expressions. 2^(-1) = 1/2 and (-1)^3 = -1. Now, comparing the values, (-4/3) is the most negative, followed by -1, then (2/5), and finally 1/2. Therefore, the correct order is (-4/3), (-1)^3, (2/5), 2^(-1), making choice D the correct answer. Choices A, B, and C are incorrect because they do not follow the correct order from least to greatest as determined by comparing the values of the expressions after simplification.
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.