50. Oil is extracted from levers in a multiple counter current extractor using ethyl ether as a solvent. The fresh levers are charged into the extractor at the rate of 1000 kg/h and contains 25.6% oil. Pure ether enters from the bottom of the extractor and overflows from the extractor contains 70% oil. The underflow contains 0.23 kg solution per kg oil free solid and is known to contain 12.8% oil. Find the flow rate of ether and % recovery of