5.3 When a 0.5-in. HSS drill on SAE 3140 steel at a feed of 0.03 ipr is used, the tool-life equation can be expressed as t=\frac{6.16 \times 10^{15}}{V^{6.5}} The hole

drilled is 2 in. deep. If the selected speed is 200 fpm, how many holes can be drilled before we need to change the drill?