Sarah uses 1 ounce of shampoo, and one half as much conditioner as shampoo daily. In two weeks, what is the total volume of shampoo and conditioner, in ounces, that Sarah will use? Let's be accurate as possible.
Sarah uses 1 + 0.5 = 1.5 ounces of hair care products daily. Two weeks is 2 * 7 = 14 days. In 14 days, Sarah will use 14 * 1.5 = 21 ounces of hair care products.
The answer: 21.