quick please

A low carbon steel bar of 147mm diameter with a length of 630mm is being tumed wath uncoated catbite insert. The observed tool tives are 24 min and 12min for cutting velocities of 90mvmin and 120mmin respectively. The feed and depth of cut are 0.2mmrrev and 2mm respectively Use the unmachined diameter to ca cylate the cutting velocity. What is the cutting vetocily in m/min when the lool lise s 20min ? [10]