GATE Mechanical Engineering (ME) 2016 Shift 2 Solved Paper

For a certain job, the cost of metal cutting is Rs. 18C/V and the cost of tooling is Rs. 270C/(TV), where C is a constant, V is the cutting speed in m/min and T is the tool life in minutes. The Taylor’s tool life equation is VT^0.25 = 150. The cutting speed (in m/min) for the minimum total cost is _______