Solve for x: x + 5 = x - 3.
- A. x = -5
- B. x = 5
- C. x = -3
- D. x = 3
Correct Answer: A
Rationale: To solve the equation x + 5 = x - 3, we aim to isolate x. By subtracting x from both sides, we get 5 = -3, which is not possible. This indicates that the equation has no solution. Therefore, the correct answer is x = -5. Choices B, C, and D are incorrect as they do not yield a valid solution when substituted back into the original equation.
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Gordon purchased a television that was 30% off its original price of $472. What was the sale price?
- A. 141.60
- B. 225.70
- C. 305.30
- D. 330.40
Correct Answer: D
Rationale: To find the sale price after a 30% discount, you first calculate the discount amount which is 30% of $472. 30% of $472 is $141.60. To find the sale price, you subtract the discount amount from the original price: $472 - $141.60 = $330.40. Therefore, the sale price of the television after a 30% discount would be $330.40. Choices A, B, and C are incorrect as they do not accurately reflect the calculated sale price after the discount.
Which is larger, feet or meters? What is the correct conversion factor between feet and meters?
- A. Feet are larger; 1 foot is 0.3048 meters
- B. Meters are larger; 1 meter is 3.28 feet
- C. Feet are smaller; 1 foot is 0.5 meters
- D. Meters are smaller; 1 meter is 2 feet
Correct Answer: A
Rationale: The correct answer is A. Feet are larger than meters. The conversion factor between feet and meters is 1 foot = 0.3048 meters. Choice B is incorrect as it states that meters are larger than feet, which is the opposite of the truth. Choice C is incorrect as it provides an incorrect conversion factor of 1 foot = 0.5 meters, which is inaccurate. Choice D is also incorrect as it suggests that meters are smaller than feet, which is not true.
What is the sum of two odd numbers, two even numbers, and an odd number and an even number?
- A. Odd + Odd = Even; Even + Even = Even; Odd + Even = Odd
- B. Odd + Odd = Odd; Even + Even = Even; Odd + Even = Even
- C. Odd + Odd = Even; Even + Even = Odd; Odd + Even = Even
- D. Odd + Odd = Odd; Even + Even = Odd; Odd + Even = Even
Correct Answer: A
Rationale: The sum of two odd numbers is even because odd numbers have a difference of 1 and adding them results in a multiple of 2. The sum of two even numbers is even because even numbers are multiples of 2. When an odd number and an even number are added, the result is odd because the even number contributes an extra 1 to the sum, making it an odd number. Therefore, the correct answer is A. Choices B, C, and D have incorrect combinations of the sum of odd and even numbers.
Which of the following best describes the data represented by this scatterplot?
- A. This is a linear association with a positive correlation.
- B. This is a linear association with a negative correlation.
- C. This is a nonlinear association.
- D. There is no association.
Correct Answer: A
Rationale: The correct answer is A. The scatterplot depicts a clear linear association with a positive correlation between the two variables. Choice B is incorrect as the correlation is positive, not negative. Choice C is incorrect because the scatterplot does not show a nonlinear association. Choice D is incorrect as there is a distinguishable association present in the data.
Robert plans to drive 1,800 miles. His car gets 30 miles per gallon, and his tank holds 12 gallons. How many tanks of gas will he need for the trip?
- A. 4 tanks
- B. 5 tanks
- C. 6 tanks
- D. 7 tanks
Correct Answer: B
Rationale: To calculate how many gallons of gas Robert needs for the 1,800-mile trip, divide the total distance by the car's mileage per gallon: 1,800 miles · 30 mpg = 60 gallons. Since his tank holds 12 gallons, Robert will need 60 gallons · 12 gallons per tank = 5 tanks of gas for the trip. Choice A (4 tanks), Choice C (6 tanks), and Choice D (7 tanks) are incorrect as they do not correctly calculate the number of tanks needed based on the car's mileage and tank capacity.