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. What is the formula for the area of a circle?

A. A = πr²
B. A = 2πr
C. A = πd
D. A = 2πd

Correct answer: A

Rationale: The correct formula for the area of a circle is A = πr², where π is a mathematical constant approximately equal to 3.14159 and r is the radius of the circle. Choice B, A = 2πr, represents the circumference of a circle, not the area. Choice C, A = πd, incorrectly uses the diameter (d) instead of the radius in the formula for area. Choice D, A = 2πd, is also related to the circumference of the circle, not the area. Therefore, option A is the only correct formula for calculating the area of a circle.

3. Kimberley earns $10 an hour babysitting, and after 10 p.m., she earns $12 an hour, with the amount paid being rounded to the nearest hour accordingly. On her last job, she worked from 5:30 p.m. to 11 p.m. In total, how much did Kimberley earn on her last job?

A. $45
B. $57
C. $62
D. $42

Correct answer: C

Rationale: Kimberley worked from 5:30 p.m. to 11 p.m., which is a total of 5.5 hours before 10 p.m. (from 5:30 p.m. to 10 p.m.) and 1 hour after 10 p.m. The earnings she made before 10 p.m. at $10 an hour was 5.5 hours * $10 = $55. Her earnings after 10 p.m. for the rounded hour were 1 hour * $12 = $12. Therefore, her total earnings for the last job were $55 + $12 = $67. Since the amount is rounded to the nearest hour, the closest rounded amount is $62. Therefore, Kimberley earned $62 on her last job. Choice A is incorrect as it does not consider the additional earnings after 10 p.m. Choices B and D are incorrect as they do not factor in the hourly rates and the total hours worked accurately.

4. Jeremy put a heavy chalk mark on the tire of his bicycle. His bike tire is 27 inches in diameter. When he rolled the bike, the chalk left marks on the sidewalk. Which expression can be used to best determine the distance, in inches, the bike rolled from the first mark to the fourth mark?

A. 3(27π)
B. 4π(27)
C. (27 ÷ 3)π
D. (27 ÷ 4)π

Correct answer: A

Rationale: The distance traveled by the bike in one complete roll of the tire is equal to the circumference, which can be calculated using the formula C = πd, where d is the diameter. Given that the diameter of the bike tire is 27 inches, the circumference is obtained by multiplying the diameter by π. As the tire rolls from the first mark to the fourth mark, it completes three full rotations (one complete roll plus two more). Therefore, the total distance rolled is 3 times the circumference, which results in 3(27π). Choice A is correct. Choice B is incorrect as it incorrectly multiplies the diameter by 4π instead of multiplying the circumference by 4. Choices C and D are incorrect as they involve dividing the diameter by a number, which is not applicable in this context.

5. Jessica buys 10 cans of paint. Red paint costs $1 per can, and blue paint costs $2 per can. In total, she spends $16. How many red cans did she buy?

A. 2
B. 3
C. 4
D. 5

Correct answer: C

Rationale: Let r be the number of red cans and b be the number of blue cans. The total cans equation is r + b = 10. The total cost equation is r + 2b = 16. By solving these equations simultaneously, we find r = 4. Therefore, Jessica bought 4 red cans. Choice A, 2 red cans, is incorrect because it does not satisfy the total cans or total cost condition. Choices B and D are also incorrect as they do not fulfill both conditions simultaneously.