Question:
How many soap cakes each measuring 7 cm × 5 cm × 2.5 cm can be placed in a box of size 56 cm × 40 cm × 25 cm?
Solution:
Volume of a soap cake $=7 \times 5 \times 2.5=87.5 \mathrm{~cm}^{3}$
Volume of the box $=56 \times 40 \times 25=56000 \mathrm{~cm}^{3}$
No. of soap cakes $=\frac{56000}{87.5}=640$ units
$\therefore 640$ cakes of soap can be placed in a box of the given size.