How can greatest common factors and least common multiples you work with fractions?

If i have a 24 in loaf of bread and i cut it into two pieces one 9 in how long was the other

I’m stuck on this equation, anyone got the answer?

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