Question

A mason constructs a wall of dimensions 270 cm× 300 cm × 350 cm with the bricks each of size 22.5 cm × 11.2 5 cm × 8.75 cm and it is assumed that 1/8 space is covered by the mortar. Then the number of bricks used to construct the wall is 

(A) 11100 (B) 11200 (C) 11000 (D) 11300

Answer 1

(B) 11200

Volume of cuboid = lbh

where, l = length, b = breadth and h = height

For wall,

Length, l = 270 cm

Breadth, b = 300 cm

Height, h = 350 cm

Volume of wall = 270 × (300) × (350) = 28350000 cm³

As 1/8 of this volume is covered by mortar, therefore 7/8 of this volume is covered by bricks.

Volume of wall covered by bricks = 7/8 (volume of wall)

= 7/8 (2835000)

= 24806250 cm³

For one brick,

Length, l = 22.5 cm

Breadth, b = 11.25 cm

Height, h = 8.75 cm

Volume of one brick = lbh

= 22.5(11.25)(8.75) cm³