The school's lemonade is $10\%$ lemon juice by volume, and the rest is sugar water. how many liters of lemon juice must be added to 20 liters of sugar water to make the school's lemonade?

Damon makes 20 cups of lemonade by mixing lemon juice and water. the ratio of lemon juice to water is shown in the tape diagram. lemon juice\text{lemon juice} lemon juice water\text{water} water how much lemon juice did damon use in the lemonade? cups