The Correct Answer and Explanation is:
The correct answer is A. The estimated BAC is .07 and the woman is impaired.
Here is a step-by-step explanation of how to arrive at this answer using the provided information and chart:
- Determine the Number of Drinks: The question states the woman had two “double” mixed drinks. A standard drink is typically defined as 1.5 ounces of 80-proof liquor. A “double” contains twice this amount, so one double drink is equivalent to two standard drinks. Therefore, the woman consumed a total of 2 x 2 = 4 standard drinks.
- Find the Initial BAC on the Chart: Using the provided “Female BAC Chart,” you locate the woman’s body weight and the number of drinks.
- Find the row for 4 drinks on the vertical axis.
- Find the column for 180 pounds on the horizontal axis.
- The intersection of this row and column shows a Blood Alcohol Content (BAC) of .10. This value represents the approximate peak BAC if the drinks were consumed quickly.
- Account for Time and Metabolism: The body metabolizes alcohol over time, reducing BAC. The drinks were consumed over a period of three hours. A common and standard estimation for alcohol metabolism is a reduction in BAC of about .015 per hour. However, for a multiple-choice question like this, a simplified model is often used. It’s common to assume that peak BAC is reached after about one hour, with metabolism occurring for the remaining time.
- Total time: 3 hours
- Time for metabolism after reaching peak BAC: 2 hours
- BAC reduction: 2 hours × .015 BAC/hour = .03
- Estimated final BAC = Initial BAC – Reduction = .10 – .03 = .07
- Determine the Level of Impairment: With an estimated BAC of .07, the woman is considered impaired. While the legal limit for intoxication in most places is .08, significant impairment of judgment, coordination, and reaction time occurs well before that level. The chart’s color-coding, where BACs of .05 and higher are in the red zone, indicates impairment. Therefore, a BAC of .07 signifies that the woman is impaired.
Combining these findings, the estimated BAC is .07, and the woman is impaired, making option A the correct choice.
