Correct Answer: A

Rationale: To convert a percentage to a decimal, you divide by 100. In this case, 38% divided by 100 equals 0.38. Moving the decimal point two places to the left converts the percentage to a decimal. Choice B is incorrect because it incorrectly moves the decimal point one place to the left. Choice C is incorrect as it moves the decimal point three places to the left. Choice D is incorrect as it does not convert the percentage to a decimal.

Correct Answer: B

Rationale: To convert from Celsius to Fahrenheit, use the formula: F = (C 9/5) + 32. Substituting 50°C: F = (50 9/5) + 32 = 122°F. Therefore, 50°C is approximately 122°F. Choices A, C, and D are incorrect because they do not reflect the accurate conversion of 50°C to Fahrenheit.

Correct Answer: C

Rationale: To find the difference between 15.7 and 9.8, you need to subtract 9.8 from 15.7. This operation results in 5.9. Therefore, the correct answer is 5.9. Choice A, 6.1, is incorrect as it represents the result of subtracting 9.8 from 15.9, not 15.7. Choice B, 8.96, is also incorrect as it is not the correct result of the subtraction provided. Choice D, 4.30, is incorrect as well, as it is not the result of subtracting 9.8 from 15.7.

Correct Answer: C

Rationale: To convert a decimal to a percent, multiply by 100. In this case, 0.64 100 = 64%. Therefore, the correct answer is C. Choice A (0.64%) is incorrect as it represents the original decimal value in percentage form. Choice B (6.4%) is incorrect as it incorrectly multiplies the decimal value by 10 instead of 100. Choice D (0.064%) is incorrect as it represents the decimal value as a fraction of 1000 instead of 100.

Correct Answer: C

Rationale: Rationale: Given formula: HR = (220 - age) * 0.65 Given heart rate: HR = 136.5 Substitute the given heart rate into the formula: 136.5 = (220 - age) * 0.65 Solve for age: 136.5 = 143 - 0.65age 0.65age = 143 - 136.5 0.65age = 6.5 age = 6.5 / 0.65 age = 10 Therefore, the patient's age is 50 (option C).