We can assume here that the milk carton is of the shape of cuboid.
The volume of cuboid can be found using the formula :

Where,
l=length =30 cm,
b=breadth =10 cm ,
h=height = 50 cm.
So plugging these values in the given formula :

So volume = 15000 cubic cm.
Answer : The milk carton can hold 15000 cubic cm of milk.