A class $1-3$ bit is used to drill at $10000$ feet with a basic drillability of $30f\frac{t}{h}r.$ Abrasiveness ${}_{H_2}$ is $20$ hours and ${}_B$ is $30$ hours. B$1$ and B$2$ are $1.$ Mud is $11\mathrm{.}4lb\frac{m}{g}al$ and the pore gradient is $9\mathrm{.}4lb\frac{m}{g}al.$ The bit costs $$3100$ and operating cost is $$5,\frac{800}{h}r.$ Trip time $($including connections$)$ is $8$ hours. $(\frac{W}{d}b)t$ is $\mathrm{.}25.)=1\mathrm{.}2,a6=(0\mathrm{.}7$

Compute the optimum operating conditions for rpm and weight on bit. $($This was in "opto.pdf$"$ if you forgot$)$