If 30% of a given number is 18, what is the full number?

Correct Answer: A

Rationale: If 30% of a number is 18, you can find the full number by dividing 18 by 0.30 (the decimal equivalent of 30%). This calculation results in 60. Therefore, the full number is 60. Choice B (30) is the result if 30% of the number itself was calculated, not the full number. Choices C (40) and D (45) are incorrect and do not align with the given information.

Correct Answer: A

Rationale: To subtract 7 7/10 from 3 4/5, first convert 3 4/5 to have the same denominator as 7 7/10. Converting 4/5 to 8/10, the subtraction becomes 7 7/10 - 3 8/10. Subtracting, 7 - 3 = 4 and 7/10 - 8/10 = -1/10. Therefore, the result is 3 4/5 - 7 7/10 = 3 9/10. Choices B, C, and D are incorrect because they do not reflect the correct subtraction of fractions and whole numbers in this scenario.

Correct Answer: A

Rationale: To calculate the number of tablets needed, divide the total daily calcium intake required (1,500 mg) by the amount of calcium in each tablet (500 mg). 1,500 mg · 500 mg = 3 tablets. Therefore, the patient should take 3 tablets to meet the 1,500 mg daily intake. Choice B, 4 tablets, is incorrect because it would exceed the required 1,500 mg. Choice C, 2 tablets, is insufficient to meet the daily intake. Choice D, 5 tablets, is also incorrect as it would exceed the required amount.

Correct Answer: C

Rationale: The temperature increased from 32°F to 145°F, resulting in a total increase of 145°F - 32°F = 113°F. Dividing this total increase by the 4 hours of cooking time gives an average rise of 113°F · 4 = 28.25°F per hour, which can be rounded to 28°F per hour. Therefore, the correct answer is 28. Choice A (20) is incorrect because it does not reflect the actual average rise in temperature per hour. Choice B (32) is incorrect as it does not consider the total temperature increase and divide it by the total hours. Choice D (37°F/hr) is incorrect as it does not match the calculated average rise in temperature per hour.

Correct Answer: C

Rationale: To convert 0.0009 to a percentage, you need to multiply by 100. This gives 0.0009 as 0.09%. Therefore, choice C is the correct answer. Choice A, 0.009%, is incorrect because it represents 0.009, not 0.0009. Choice B, 0.9%, is incorrect as it represents 0.9, which is a different value. Choice D, 9%, is also incorrect as it represents 9, not 0.0009.

Correct Answer: B

Rationale: When multiplying a positive integer by a negative integer, the product will always be negative. This is a fundamental rule of arithmetic. The sign of the product is determined by the rule that states a positive number multiplied by a negative number results in a negative number. Therefore, the statement that the product will always be negative is always true when multiplying positive and negative integers. Choice A is incorrect because the product is not always positive when multiplying positive and negative integers. Choice C is incorrect because the product is not dependent on the specific numbers but on the signs of the integers being multiplied. Choice D is incorrect as positive and negative integers can be multiplied.

Correct Answer: A

Rationale: If 30% of a number is 18, you can find the full number by dividing 18 by 0.30 (the decimal equivalent of 30%). This calculation results in 60. Therefore, the full number is 60. Choice B (30) is the result if 30% of the number itself was calculated, not the full number. Choices C (40) and D (45) are incorrect and do not align with the given information.

Correct Answer: D

Rationale: Rationale: 1. 7 is divisible by 1 because every number is divisible by 1. 2. 7 is divisible by 7 because any number is divisible by itself. 3. 7 is not divisible by 2 because 7 is an odd number and not divisible by 2. 4. 7 is not divisible by 3 because the sum of the digits of 7 (7) is not divisible by 3. Therefore, 7 is divisible by 1, 7, and itself (7), making the correct answer D) 2, 3, and 7.

Correct Answer: A

Rationale: To convert Celsius to Fahrenheit, the formula F = (9/5)C + 32 is used. Substituting 26°C into the formula: F = (9/5)(26) + 32 = 78.8°F, which rounds to 78°F. Therefore, the correct answer is 78°F. Choice B (72°F), Choice C (80°F), and Choice D (85°F) are incorrect as they do not result from the correct conversion calculation.