I'm sorry the picture is blurry. Could you post another one.
Answer: 120 cm
Step-by-step explanation:
V = a^2 h/3
Set equations for both containers:
Condition one: $y=2x$
Condition two: $(y-3)=4.5(x-2)$
plug in $y$ from condition one into the second equation:
$2x-3=4.5x-9$
simplify gives: $2.5x=6$
$\boxed{x=2.4}$
$\boxed{y=4.8}$