A slurry of flaked soybeans weighing 100 kg contains 75 kg inert solids and 25 kg solution with 10% oil and 90% weight solvent hexane. This slurry is contacted with 100 kg pure hexane in a single stage so that the value of retention for the outlet underflow is 2.0 kg of insoluble solid per kg solvent in the adhering solution. What is the composition of underflow leaving the extraction stage in percent by weight oil? choices: a. 68 percent b 0.68 percent c. 68 percent d. 0.608 percent