Question

Hameed has built a cubical water tank with lid for his house, with each outer edge 1.5m long. He gets the outer surface of the tank excluding the base, covered with square tiles of side 25 cm. Find how much be would spend for the tiles, if the cost of tiles is Rs. 360 per dozen.

Answer 1

Edge of cubical tank = 1.5 m

$\therefore \text{Area of 4 walls}=4(side{)}^2=4(1.5{)}^2{m}^2$

$=4\times 2.25=9m^2$

$\text{Area of lid}=(1.5{)}^2=2.25m^2$

$\therefore \text{Total surface area}=9+2.25=11.25m^2$

$\text{Edge of square tile}=25cm=0.25m$

$\therefore \text{Area of 1 tile}=(0.25{)}^2=.0625m^2$

$\therefore \text{Number of tiles use}=\frac{\text{Total area}}{\text{Area of 1 tile}}$

$=\frac{11.25}{0.0625}=\frac{1125\times 10000}{100\times 625}=180$

$\therefore \text{Cost of 12 tiles}=Rs360$

$\therefore \text{Cost of 180 tile}=\frac{360\times 180}{12}=Rs5400$