Final answer:
The price for 2n grams of vitamins remains the same as the price for n grams of vitamins.
Step-by-step explanation:
The price for 2n grams of vitamins can be determined by using the information provided for n grams of vitamins. Let's assume that the price for n grams of vitamins is x dollars.
Since the price remains the same, the cost for 2n grams of vitamins will also be x dollars.