Question

How many lead shots, each 0.3 cm in diameter, can be made from a cuboid of dimensions 9 cm × 11 cm× 12 cm?
(a) 7200
(b) 8400
(c) 72000
(d) 84000

Answer 1

(d) 84000

$$\begin{gathered} \mathrm{Number}\mathrm{of}\mathrm{lead}\mathrm{shots}=\frac{\mathrm{volume}\mathrm{of}\mathrm{cuboid}}{\mathrm{volume}\mathrm{of}1\mathrm{lead}\mathrm{shot}} \\ =\frac{9\times 11\times 12}{{\displaystyle \frac{4}{3}}\times {\displaystyle \frac{22}{7}}\times 0.15\times 0.15\times 0.15} \\ =\frac{9\times 11\times 3\times 3\times 7}{22\times 0.15\times 0.15\times 0.15} \\ =84000 \end{gathered}$$