Question

A bathroom is in the form of a cuboid of dimension 3m*3m*6m m.How many square tiles are required to fix to all the faces if side of a tile is 5cm

Answer 1

Use the formula for calculating the surface area of a cuboid. It has 6 faces, 2 faces like a square and the other 4 faces are like a rectangle.

$S.A= (2(l^2)+4(l\times b))= (2(3\times 3)+ 4 ( 6\times 3)= 90m^2$.

You change the face of a side to meters

$5cm \times \frac{1m}{100cm}= 0.05m.$

Then you find area of the square tile

$A=l^2=(0.05^2)= 0.0025 m^2$, then using the formula below where n is number of tiles, $s_a$ is surface area of cuboid and $a_t$ is area of 1 tile

$n=\frac{s_a}{a_t} =\frac{90}{0.0025} = 3600 tiles.$