Calculating radius as a function of volume and as a function of time

A gas tank on a dock has a small puncture and is leaking gas at a rate of 1 cm^3/min into a lake. it forms a circular slick that is 1mm thick on the surface of the water.

a) find the amount of gas leaked as a function of time.

b) State the radius of the slick as a function of its volume.

c) State the radius of the slick as a function of time.

d) what is the radius of the slick after 40 minutes?

I'm having trouble figuring out how to approach this question,even if someone can give me a guideline or help me with part of it i'm sure i could figure out the rest based on that. Thank you :)