A doctor orders 3.5 mL of phenobarbital elixir. If the phenobarbital elixir is available as 60. mg per 7.5 mL, how many milligrams is given to the patient?

Question

Express your answer to two significant figures and include the appropriate units.

Answer 1

To solve this problem, we can create a proportion:

(60 mg / 7.5 mL) = (x mg / 3.5 mL)

Cross-multiplying, we get:

7.5 mL * x mg = 60 mg * 3.5 mL

Simplifying, we find:

7.5x = 210

Dividing both sides by 7.5, we find:

x = 28

Therefore, the patient is given 28 mg of phenobarbital elixir.