A factory puts 4/5 of a gallon of vinegar into each batch of salad dressing. How many gallons of vinegar will be used in 9 batches?

Write your answer as a fraction or as a whole or mixed number.

1 answer

To find out how many gallons of vinegar will be used in 9 batches, we can multiply the amount of vinegar per batch by the number of batches.

The amount of vinegar per batch is \( \frac{4}{5} \) gallons. The number of batches is 9.

We can set up the multiplication as follows:

\[ \text{Total vinegar} = \left(\frac{4}{5}\right) \times 9 \]

To multiply a fraction by a whole number, we can express the whole number as a fraction:

\[ 9 = \frac{9}{1} \]

Now we can multiply:

\[ \text{Total vinegar} = \frac{4}{5} \times \frac{9}{1} = \frac{4 \times 9}{5 \times 1} = \frac{36}{5} \]

Now, we can convert \( \frac{36}{5} \) into a mixed number. To do this, we divide 36 by 5:

\[ 36 \div 5 = 7\quad \text{(with a remainder of 1)} \]

So, that means:

\[ 36 = 5 \times 7 + 1 \]

This tells us that \( \frac{36}{5} \) can be expressed as:

\[ 7 \frac{1}{5} \]

Therefore, the total amount of vinegar used in 9 batches is

\[ \frac{36}{5} \text{ gallons} \text{ or } 7 \frac{1}{5} \text{ gallons}. \]

Final answer: \( \frac{36}{5} \) gallons or \( 7 \frac{1}{5} \) gallons.