Respuesta :

since 30 and 45 can both be divided by 5, just divided them and is 6:9 and 6 and 9 can be both divided by 3,so the final answer should be 2ml:3ml
[tex]\large\begin{array}{I} \mathtt{ \dfrac{30~ml}{45~ml}=\dfrac{2 \times 3 \times 5~ml}{3 \times 3 \times 5~ml}= \boxed{\dfrac{2}{3}} } \end{array}[/tex]