Question

If 1/2 cup of water fills 2/3 of a plastic container, how many containers will 1 cup full?

Answer 1

1 cup will fills double than 1/2 cup, so:

$\frac{2}{3}\cdot2=\frac{4}{3}$

With 1 cup you will be able to fills 4/3, in other words 1 full container and 1/3 of another.