You are furnished with three sizes of particles. One is gravel with porosity of 0.32, the second is a coarse grained sand with porosity of 0.37, and the third is a fine grained sand with porosity of 0.23. If the coarse grained sand will fill the voids left by the gravel, and the fine grained sand will fill the void left by the coarse grained sand,
(a) what bulk volumes of gravel, coarse grained sand, and fine grained sand will be required to make a packing with a bulk volume of 1ft^3?
(b) What will be the porosity of the mixture?