## Elementary Technical Mathematics

8$\frac{2}{3}$ min
Let the cutting tool on the lathe moves $\frac{3}{128}$ in. along the piece The piece revolves at 45 revolution per minute We need to find the time it will take to turn a 9$\frac{9}{64}$ in length stock in one operation therefore No of revolution = 9$\frac{9}{64} \div$ $\frac{3}{128}$ in = $\frac{585}{64} \div$ $\frac{3}{128}$ in = $\frac{585}{64} \times$ $\frac{128}{3}$ in = 390 revolutions Time = 390 revolution $\times$ $\frac{1 min}{45 revolution}$ =$\frac{26}{3}$ min =8$\frac{2}{3}$ min