How many lead shots each 3 mm 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: Option D

Solution(By Examveda Team)

Volume of each lead shot :
$$\eqalign{ & = \left[ {\frac{4}{3}\pi \times {{\left( {\frac{{0.3}}{2}} \right)}^3}} \right]{\text{ c}}{{\text{m}}^3} \cr & = \left( {\frac{4}{3} \times \frac{{22}}{7} \times \frac{{27}}{{8000}}} \right){\text{ c}}{{\text{m}}^3} \cr & = \frac{{99}}{{7000}}{\text{ c}}{{\text{m}}^3} \cr} $$
∴ Number of lead shots :
$$\eqalign{ & = \left( {9 \times 11 \times 12 \times \frac{{7000}}{{99}}} \right) \cr & = 84000 \cr} $$