Correct Answer: B

Rationale: To administer 20 mg of the medication, you would need 25 mL. This calculation is derived from the concentration of 4 mg per 5 mL. By setting up a proportion, you can determine that for 20 mg, 25 mL must be administered as follows: (20 mg / 4 mg) = (x mL / 5 mL). Solving for x results in x = 25 mL. Choice A is incorrect because it miscalculates the proportion. Choices C and D are incorrect as they do not account for the correct concentration of the medication.

Correct Answer: A

Rationale: To convert a decimal to a percentage, you move the decimal point two places to the right and add a percentage sign. Therefore, 0.608 as a percent is 60.8%. The correct answer is A. Choice B (68%) is incorrect because it represents the percentage for a different decimal value. Choice C (0%) is incorrect as it represents 0 as a percentage, not 0.608. Choice D (6%) is incorrect as it also represents a different decimal value, not 0.608.

Correct Answer: A

Rationale: To find the value of x, set up the proportion 7/9 = x/63. Cross multiply to get 7*63 = 9*x. This simplifies to 441 = 9x. Divide both sides by 9 to solve for x, giving x = 49. Therefore, the correct answer is A. Choice B (x = 39), Choice C (x = 50), and Choice D (x = 59) are incorrect as they do not match the correct calculation based on the proportion set up.

Correct Answer: A

Rationale: To add fractions, find a common denominator, which in this case is 40. Convert each fraction to have the common denominator: 7/8 = 35/40, 9/10 = 36/40, and 6/5 = 48/40. Add these fractions to get 119/40. Simplify this improper fraction to a mixed number, which is 3 & 39/40. Choice B and C are incorrect as they do not represent the sum of the fractions. Choice D is incorrect; the whole number part should be 3, not 2.

Correct Answer: A

Rationale: To add fractions, you need a common denominator. In this case, the common denominator is 57 * 75 = 4275. So, (47*75 + 65*57) / 4275 = (3525 + 3705) / 4275 = 7230 / 4275. Simplifying this fraction gives 1 23/35. Choice B: 2 1/3 is incorrect as the correct result is not a mixed number. Choice C: 1 2/3 is incorrect as it does not match the simplified result of the expression. Choice D: 1 5/6 is incorrect as it is a different value from the correct result obtained by adding the fractions.