### Instruction: Don has a bottle of milk with $\frac{1}{5}$ of a gallon of milk in it. Don's friend Rachel drinks $\frac{2}{3}$ of the milk he has. How many gallons of milk did Rachel drink?### Response: To solve this problem, I need to find out how much milk Rachel drank as a fraction of a gallon.
I know that Rachel drank $\frac{2}{3}$ of what Don had, so I can multiply $\frac{2}{3}$ by $\frac{1}{5}$ to get the fraction of a gallon that Rachel drank.
To multiply two fractions, I multiply the numerators and the denominators separately.
So I get $\frac{2}{3} \times \frac{1}{5} = \frac{2 \times 1}{3 \times 5} = \frac{2}{15}$.
This means that Rachel drank $\frac{2}{15}$ of a gallon of milk.
If I want to convert this fraction to a decimal, I can divide the numerator by the denominator.
So I get $\frac{2}{15} \approx 0.133$.