Please I need help ASAP! This is the problem: Cowen cites the deposition rate of BIF in the Hamersley Basin of Australia as 30 million metric tonnes per year. He says the ore is 55% iron (volume); iron has a density of 8 g/cm^3. Assume the rest of the ore is made of silica, which has a density of 2.6 g/cm^3. Using these data, calculate the volume of ore that was deposited aannually at Hamersley (recall that density = mass per unit volume). The Hamersley Basic is roughly circular ((we were told to consider it cylinder)), about 400 km in diameter. How thick was an annual layer of ore? My teacher said we need to get average density, then volume, finally thickness. But I still have no idea how to go about doing this homework!!