Question

a rectangular swimming pool is 60m wide and 20m deep is to be tiled with tiles of dimensions 40cm by 50cm . find the number of tiles required for the swimming pool

Answer 1

The rectangular swimming pool:
length= 30m
breadth=20m
height=1.5m
the total surface area of pool= lateral surface area + area of base {l x b}

2h[l+b] +l x b
2 x 1.5 [30+20] + 30 x 20 = 750 m sq
SQUARE TILE 
side of square=50cm=0.5m
area of 1 square tile = a x a = 0.5 x 0.5 = 0.25m sq 
no of tiles = area of pool / area of one tile.

no of tiles = 750/0.25 = 3000
therefore 3000 tiles are required.

Hope it may helps you

Answer 2

$area \: of \: rectengular \: swimming \: pool \: = 60 \times 20 \\ \\ 1200m {}^{2} = 1200 \times 10000 = 12000000cm {}^{2} \\ \\ area \: of \: each \: tile \: = 40 \times 50 \\ \\ = 2000cm {}^{2} \\ \\ therefore \: number \: of \: tiles = \frac{12000000}{2000} \\ \\ = \frac{12000}{2} \\ \\ = 6000 \\ \\ hope \: it \: helps...$