Question 1: let x be the water content x+(1-x) * 2.75 =1.84x = 0.52, and the water content is 52%. Question 2: The density of dry sand sample is 1. 66g/cm3, and the specific gravity of sand is 2. 70g/cm3 sample sand accounts for the total specific gravity 1.66/2.7=0.6 148, the porosity accounts for 0.3852, and the saturation is 0 when the saturation increases to 0. 60, that is, when water accounts for 60% of 0.3852, that is, when 0.3852 * 60% = 0.2311,the sample density =1.66+0.231= 650.