To determine how many quarts of rubbing alcohol are needed for 1,280 bottles of window cleaner, we need to start with the amounts specified for the formula for 8 bottles and then scale up to 1,280 bottles.
The formula for 8 bottles calls for:
- 6 cups of rubbing alcohol.
Now, we need to find out how much rubbing alcohol is needed for 1,280 bottles.
First, let's find out how many times 8 bottles fit into 1,280 bottles: \[ \frac{1280 \text{ bottles}}{8 \text{ bottles}} = 160. \]
This means we need 160 times the amount of each ingredient in the original formula for 8 bottles.
Next, we calculate the total amount of rubbing alcohol for 1,280 bottles: \[ 6 \text{ cups} \times 160 = 960 \text{ cups of rubbing alcohol}. \]
Now we need to convert cups to quarts. There are 4 cups in 1 quart, so we convert cups to quarts: \[ \frac{960 \text{ cups}}{4 \text{ cups/quart}} = 240 \text{ quarts}. \]
Thus, the formula for 1,280 bottles of window cleaner calls for 240 quarts of rubbing alcohol.
The correct answer is 240 quarts.