GATE2016-2-51

Question

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 tool cost is