Amoxicillin is prescribed at 1,200 mg per dose. The concentration is 400 mg per 5 mL. How many milliliters are required per dose?

Amoxicillin is prescribed at 1,200 mg per dose. The concentration is 400 mg per 5 mL. How many milliliters are required per dose?

• A. 5 mL
• B. 10 mL
• C. 15 mL
• D. 20 mL

Answer: (C)

The amount of liquid needed scales with the dose using the given concentration. If 400 mg is in 5 mL, then 1,200 mg is three times that amount. So you multiply the volume by three: 3 × 5 mL = 15 mL. Another way is to use the concentration in mg per mL: 400 mg/5 mL equals 80 mg per mL. To reach 1,200 mg, you need 1,200 ÷ 80 = 15 mL. Therefore, 15 mL are required per dose.

The amount of liquid needed scales with the dose using the given concentration. If 400 mg is in 5 mL, then 1,200 mg is three times that amount. So you multiply the volume by three: 3 × 5 mL = 15 mL. Another way is to use the concentration in mg per mL: 400 mg/5 mL equals 80 mg per mL. To reach 1,200 mg, you need 1,200 ÷ 80 = 15 mL. Therefore, 15 mL are required per dose.