If d=depth of cut in mm, f=feed in mm/stroke, n=stroke/min, l=length of stroke in mm, m= ratio of return stroke time to cutting stroke time, then find the formula for metal removal rate.

• A. f*d*l*n*(m+1)
• B. f*d*l*n*m
• C. f*d*l*n*m/1000
• D. none of the mentioned