Helium balloon in water and air

[greset]

If I were to let go of a Helium balloon with a volume of 3 liter at a depth of 10 meters, how do i calculate te time it will take the balloon to reach an altitude of a 100 meters in the air? And what changes if its not helium but hydrogen for instance?

hope anyone can help me with this

 

[Hootenanny]

Welcome to PF greset,

This smells like homework to me...

What have you attempted thus far?