Final answer:
The customer who drank both beer and whiskey had consumed more alcohol.
Step-by-step explanation:
To compare the amount of alcohol consumed by the two customers, we need to calculate the total volume of alcohol each customer consumed. The first customer drank two bottles of beer, each containing 341 mL of beer. So, the first customer consumed 2 x 341 = 682 mL of beer. The second customer had two drinks: beer and a shot of whiskey. The customer drank two bottles of beer, totaling 682 mL of beer, and one shot of whiskey, equal to 43 mL. Therefore, the second customer consumed 682 + 43 = 725 mL of alcohol. Hence, the second customer, who drank both beer and whiskey, had consumed more alcohol than the first customer who only drank beer.