SmartServe Ontario Practice Exam 2025 - Free SmartServe Practice Questions and Study Guide.

The Blood Alcohol Concentration (BAC) is expressed as a percentage of alcohol per 100 mL of blood. To calculate BAC, you would convert the amount of alcohol in the blood into a percentage.

In this scenario, if there are 50 mg of alcohol in 100 mL of blood, you first need to understand that 50 mg is equivalent to 0.05 grams (since there are 1000 mg in a gram). When you take this amount of alcohol (0.05 grams) and express it in terms of percent, it results in a BAC of 0.05%.

This is consistent with how BAC is typically quantified: a BAC of 0.05 means that there are 0.05 grams of alcohol in 100 mL of blood. Therefore, the correct answer showing a BAC of 0.05 accurately reflects the amount of alcohol measured in this person's blood.

Understanding these calculations is essential since BAC levels are critical for determining a person's level of impairment and adherence to legal drinking limits.