Question

if the volume of the oceans combined is about 1,350,000,000 cubic km by what height with the oceans increase if all the ice melted

Answer 1

depends on the amount of ice, doncha think?

Also, you need to know the surface area of the oceans. A large ocean will rise less than a small one for the same amount of ice.

Also, a given volume of ice produces less volume when melted.

There is so much missing in this question.