The values of n and C are

Question

In a machining test, a cutting speed of 100 m/min indicated the tool life as 16 min and a cutting speed of 200 m/min indicated the tool life as 4 min. The values of n and C are                                                     

            (a) 0.5 and 200            (b) 0.25 and 200

            (c) 0.5 and 400            (d) 0.25 and 400