Lizzy: Adonis is playing a prank on his dad by replacing his shampoo with hot sauce. Every day, after his dad showers, Adonis replaces the shampoo with 1/2 an ounce of hot sauce. He knows his dad uses 1 oz of shampoo a day from a new 10 oz bottle that no one else uses. After 4 days, what percentage of the liquid in the bottle is hot sauce?.
Me: Hmmm, let me think. I think this is the detailed solution:
Each day, the shampoo bottle goes down 1 / 2 an ounce because 1 - (1 / 2) = 1 / 2. After four days the shampoo bottle is 2 ounces lower because 4 x (1 / 2) = 2. After four days, the shampoo bottle has 8 ounces of liquid left because 10 - 2 = 8. After four days the shampoo bottle has 2 ounces of hot sauce 4 x (1 / 2) = 2. The proportion of hot sauce in the bottle is .25 because 2 / 8 = .25. The percentage of hot sauce is 25% because .25 x 100 = 25. Final answer: 25.