5ℓ of apple juice from a jug is used to fill up an empty container measuring 100 mm by 9 cm by 40 cm completely. What is the volume of apple juice left in the jug?

Hint: 1 L is 1000 𝑐𝑚³

container: 100 mm by 9 cm by 40 cm

or
10 cm by 9cm by 40 cm
volume = 10*9*40 cm^3
= 3600 cm^3

you had 5000 cm^3 (5 l)
so you have 1400 cm^3 left