Short Answer 
To calculate Blood Alcohol Concentration (BAC), first identify the total alcohol consumed, which is 1.8 oz (51 grams). Using the formula BAC = (Grams of Alcohol) / (Weight in grams x Gender Constant), and applying it to a 140-pound male, the calculated BAC is 0.11%.
Step 1: Understand Alcohol Consumption
To calculate the Blood Alcohol Concentration (BAC), it is crucial to account for the amount and type of alcohol consumed. In this case, the individual consumed:
- Two 12-ounce beers, which contain 0.6 oz of alcohol each.
- One 1.5 oz shot of 40% liquor, which also has 0.6 oz of alcohol.
- In total, he consumed 1.8 oz of alcohol.
Step 2: Convert Alcohol Quantity to Grams
Once you have the total amount of alcohol consumed in ounces, convert this figure to grams. The conversion is straightforward:
- 1.8 oz of alcohol is equivalent to 51 grams of alcohol.
- This is a key figure needed for calculating the BAC.
Step 3: Calculate the BAC
To find the BAC, use the following formula: BAC = (Grams of Alcohol) / (Weight in grams x Gender Constant). For the individual weighing 140 pounds (63560 grams) and using the male constant of 0.68:
- Set up the equation: 51 / (63560 x 0.68).
- Calculate the result, which gives 0.0011.
- Finally, multiply by 100 to convert to BAC percentage: 0.11.