how do you convert f to c and c to f

ATI TEAS 7

Practice Math TEAS TEST

1. How do you convert Fahrenheit to Celsius and Celsius to Fahrenheit?

A. Fahrenheit to Celsius: Subtract 32, then divide by 1.8; Celsius to Fahrenheit: Multiply by 1.8, then add 32
B. Fahrenheit to Celsius: Subtract 32, then divide by 2; Celsius to Fahrenheit: Multiply by 1.8, then add 20
C. Fahrenheit to Celsius: Multiply by 2, then add 32; Celsius to Fahrenheit: Subtract 32, then divide by 1.8
D. Fahrenheit to Celsius: Subtract 30, then divide by 1.8; Celsius to Fahrenheit: Multiply by 2, then add 32

Correct answer: A

Rationale: To convert Fahrenheit to Celsius, you start by subtracting 32 from the Fahrenheit temperature and then divide the result by 1.8. This formula accounts for the freezing point of water at 32°F and the conversion factor to Celsius. To convert Celsius to Fahrenheit, you multiply the Celsius temperature by 1.8 and then add 32. This process takes into consideration the conversion factor from Celsius to Fahrenheit and the freezing point of water. Choice B is incorrect as dividing by 2 instead of 1.8 would yield an inaccurate conversion. Choice C is incorrect as it involves incorrect operations for both conversions. Choice D is incorrect as subtracting 30 instead of 32 for Fahrenheit to Celsius and multiplying by 2 instead of 1.8 for Celsius to Fahrenheit would provide incorrect results.

2. To rent tablecloths from a rental vendor, there is an initial charge of $40. There is an additional charge of $5 per circular tablecloth (c) and $3.50 per rectangular tablecloth (r). Which of the following represents the total cost (T) to rent tablecloths?

A. 5r + 3.5c - 40 = T
B. 5c + 3.5r + 40 = T
C. 5c + 3.5r - 40 = T
D. 5r + 3.5c + 40 = T

Correct answer: B

Rationale: The total cost (T) consists of the initial charge of $40 plus the additional charges based on the number of tablecloths. The correct expression for T is T = 5c + 3.5r + 40. This accounts for the $5 per circular tablecloth (5c), $3.50 per rectangular tablecloth (3.5r), and the initial $40 charge. Choice A is incorrect as it subtracts the initial charge instead of adding it. Choice C is also incorrect as it subtracts the initial charge and has the coefficients in the wrong positions. Choice D adds the initial charge at the end instead of at the beginning, making it incorrect. Therefore, choice B is the correct representation of the total cost to rent tablecloths.

3. Bridget is repainting her rectangular bedroom. Two walls measure 15 feet by 9 feet, and the other two measure 12.5 feet by 9 feet. One gallon of paint covers an average of 32 square meters. Which of the following is the number of gallons of paint that Bridget will use? (There are 3.28 feet in 1 meter.)

A. 0.72 gallons
B. 1.43 gallons
C. 4.72 gallons
D. 15.5 gallons

Correct answer: B

Rationale: First, convert the dimensions to meters: 15 ft. × (1 m/3.28 ft.) = 4.57 m; 9 ft. × (1 m/3.28 ft.) = 2.74 m; 12.5 ft. × (1 m/3.28 ft.) = 3.81 m. Next, find the total area in square meters: total area = 2(4.57 m × 2.74 m) + 2(3.81 m × 2.74 m) = 45.9 m². Finally, convert the area to gallons of paint: 45.9 m² × (1 gallon/32 m²) = 1.43 gallons. Therefore, Bridget will need 1.43 gallons of paint to repaint her bedroom. Choices A, C, and D are incorrect because they do not accurately calculate the required amount of paint based on the given dimensions and the coverage area of one gallon of paint.

4. Simplify the expression: 2x + 3x - 5.

A. 5x - 5
B. 5x
C. x - 5
D. 2x - 5

Correct answer: A

Rationale: To simplify the expression 2𝑥 + 3𝑥 - 5, follow these steps: Identify and combine like terms. The terms 2𝑥 and 3𝑥 are both 'like terms' because they both contain the variable 𝑥. Add the coefficients of the like terms: 2𝑥 + 3𝑥 = 5𝑥. Simplify the expression. After combining the like terms, the expression becomes 5𝑥 - 5, which includes the simplified term 5𝑥 and the constant -5. Thus, the fully simplified expression is 5𝑥 - 5, making Option A the correct answer. This method ensures all terms are correctly simplified by combining similar elements and retaining constants.

5. A certain exam has 30 questions. A student gets 1 point for each question answered correctly and loses half a point for each question answered incorrectly; no points are gained or lost for questions left blank. If x represents the number of questions a student answers correctly and y represents the number of questions left blank, which of the following expressions represents the student's score on the exam?

A. x - y/2
B. x - y
C. 30 - (x + y)
D. 30 - x - y/2

Correct answer: A

Rationale: The student's score is calculated by adding the points earned for correct answers (x) and subtracting the points lost for incorrect answers (y/2). Therefore, the expression for the student's score on the exam is x - y/2. Option A is correct because it accurately represents this calculation. Option B (x - y) is incorrect as it does not account for the penalty of losing half a point for each incorrect answer. Option C (30 - (x + y)) is incorrect as it subtracts the total number of questions from the sum of correct and blank answers, which does not represent the scoring system. Option D (30 - x - y/2) is also incorrect as it incorrectly subtracts x from 30 and then deducts y divided by 2, which is not the correct scoring method for the exam.