The external dimensions of a closed wooden box are 48 cm, 36 cm, 30 cm. The box is made of 1.5 cm thick wood. How many bricks of size 6 cm × 3 cm×0.75 cm can be put in this box?
Given,
External dimensions of closed wooden box = 48cm×36cm×30cm
Thickness of wood = 1.5 cm
So inner dimensions of box would be = [(48-3)×(36-3)×(30-3)]
= 45cm×33cm×27cm
Volume of box = 45×33×27 = 38880 cm3
Volume of a brick = 6×3×0.75 = 13.5 cm3
So, number of bricks can put in box = 
17