A 200 kg/h feed containing 35% of acetic acid (A) and 65% of water (B) is to be extracted using a counter-current multistage extraction process. A 800 kg/h solvent stream containing 2% acetic acid and 98% isopropyl ether (C) is used. The exiting raffinate stream should contain 8 wt% of acetic acid. Using the graph in Appendix II, estimate the number of equilibrium stages needed for this counter-current multistage extraction process. XY 09 0.8 03 06 05 04 0.3 02 01 0 02 DA 05 LE 0.8 XAYA 1