I don't know what to do at all...I had an idea, but I got stuck, BIG TIME. Please show me what to do step by step, Thanks.

Sand falls from a hopper at a rate of 0.1 cubic meters per hour and forms a conical pile beneath. If the side of the cone makes an angle Pi/6 radians with the vertical, find the rate at which the height of the cone increases. Give your answer in terms of "h," the height of the pile in meters.

Thanks for any help.