Question

little johnny is a 5 - year - old male who weighs 42 pounds. he hurt his leg today after falling from his trampoline. the provider would like you to address his pain by giving him some ibuprofen. you have 100mg/5ml of ibuprofen available in your medication room. how many mls are you giving johnny?

Explanation:

Step1: Set up proportion

Let $x$ be the volume in mL. We know the concentration is 100mg/5mL and we need to give 50mg. The proportion is $\frac{100\text{ mg}}{5\text{ mL}}=\frac{50\text{ mg}}{x\text{ mL}}$.

Step2: Cross - multiply

$100x = 50\times5$.

Step3: Solve for $x$

$100x=250$, so $x=\frac{250}{100}=2.5$ mL.

Answer:

2.5 mL