A 2.09 cm thick bar of soap is floating on a water surface so that 1.50 cm of the bar is underwater. Bath oil of specific gravity 0.639 is poured into the water and floats on top of the water. What is the depth of the oil layer when the top of the soap is just level with the upper surface of the oil? Given the thicknesses and distances of the materials i have found that the distance between the waters surface and that of the highest point of the bar of soap is : 2.09-1.50=5.9e-3m since the bath oil floats on the water i figured that the depth of the bath oil will be the distance of the part of soap that is petruding out of the water. However this is not the case. I also know that the depth or volume is not the petruding distance multiled of divided by the density of the liquid. Any help??