\( 1 \leftarrow \) The Blood Alcohol Concentration (BAC) of a person who has been drinking is given by the formula BAC \( =\frac{\text { (ounces } \times \text { percent alcohol } \times 0.075)}{\text { body weight in } \mathrm{lb}}-(\mathrm{hours} \) of drinking \( \times 0.015) \). In two hours, a \( 200-\mathrm{lb} \) person has drunk 516 -oz beers, each having a \( 3.6 \% \) alcohol content. The formula would then read BAC \( =\frac{[(5 \times 16) \times 3.6 \times 0.075]}{200}-(2 \times 0.015) \). Answer parts (a) and (b) below. (a) The person's BAC is 0.078 . (Round to the nearest thousandth as needed.) (b) Find the BAC for a 125 -pound person who, in three hours, has drunk three 12-ounce beers, each having a \( 3.0 \% \) alcohol content. The person's BAC is \( \square \). (Round to the nearest thousandth as needed.)

**Step 1. Write the BAC formula:** \[ \text{BAC} = \frac{(\text{ounces} \times \text{percent alcohol} \times 0.075)}{\text{body weight in lb}} - (\text{hours of drinking} \times 0.015) \] **Step 2. Identify the values for part (b):** - Body weight: \(125\) lb - Hours drinking: \(3\) hours - Number of beers: \(3\) - Ounces per beer: \(12\) oz - Total ounces consumed: \[ 3 \times 12 = 36 \text{ oz} \] - Percent alcohol: \(3.0\%\) (use as \(3.0\) in the formula) **Step 3. Substitute the values into the formula:** \[ \text{BAC} = \frac{(36 \times 3.0 \times 0.075)}{125} - (3 \times 0.015) \] **Step 4. Compute the numerator:** - Multiply ounces by percent alcohol: \[ 36 \times 3.0 = 108 \] - Multiply by 0.075: \[ 108 \times 0.075 = 8.1 \] **Step 5. Divide by the body weight:** \[ \frac{8.1}{125} = 0.0648 \] **Step 6. Compute the elimination part:** \[ 3 \times 0.015 = 0.045 \] **Step 7. Compute the final BAC:** \[ \text{BAC} = 0.0648 - 0.045 = 0.0198 \] **Step 8. Round to the nearest thousandth:** \[ 0.0198 \approx 0.020 \] The person's BAC is \(0.020\).