A more thorough explanation:

Blood Alcohol Content (BAC) is the amount of alcohol in a person's bloodstream. It is measured in milligrams per deciliter (mg/dL) or as a percentage. For example, a BAC of 0.08% means that there are 0.08 grams of alcohol per 100 milliliters of blood.

Alcohol is processed by the liver at a rate of about one standard drink per hour. A standard drink is equivalent to 12 ounces of beer, 5 ounces of wine, or 1.5 ounces of liquor. When a person drinks faster than the liver can process, their BAC increases, and they become intoxicated.

The effects of intoxication vary depending on the BAC level and can range from slurred speech and loss of coordination to vomiting, blackouts, coma, or death. In most states, it is illegal to drive with a BAC of 0.08% or higher.

Factors such as weight and health can affect a person's BAC. For example, a person who weighs 120 pounds will typically reach a BAC of 0.08% after two to three drinks, while a person who weighs 180 pounds will reach the same BAC after three to four drinks.

Police officers may use blood alcohol tests to measure a person's BAC. For example, a breathalyzer test measures the amount of alcohol in a person's breath and estimates their BAC.

Example: John had four beers in two hours. His BAC is likely to be higher than 0.08%, making it illegal for him to drive.

Example: Sarah weighs 140 pounds and had two glasses of wine. Her BAC is likely to be around 0.05%, which is below the legal limit for driving.

These examples illustrate how a person's BAC can vary depending on their weight, the amount of alcohol they consume, and the time frame in which they consume it. It is important to understand the risks of drinking and driving and to always have a designated driver or alternative transportation.