Question

A wall whose height and thickness are 20metres and 1/4 metres is to be built of bricks which length,breadth and height are 25cm,15cm and 12cm.find the number of bricks?

Answer 1

Solu: Given that : wall is to be built using bricks,
so, Bricks dimensions are given ,i,e; . L = 20cm, B = 16cm, H = 8cm .
Let ,
Bricks are in shape of cuboid
So, Total surface area of cuboid = 2(lb+bh+lh) 
=2(20 × 16 + 16 × 8 + 20 × 8)
=2(320 + 128 + 160) 
=(640 + 128 + 160)
=928 cubic centimeters
=928÷1000000= 00.0928 m 
Now, Area of wall =2( l+b)×h
=2(10+64)×5
=2(74)×5
=148×5
=740 cubic meters
So,. area of 1 brick = 00.0928÷740=0.7974 sq . m 
=area of 1 brick × area of wall
=0.7974 × 740 = 590 bricks are required