Hameed has built a cubical water tank with lid for his house, with each other edge 1.5 m long.

Given that

Hameed is getting 5 outer faces of the tank covered with tiles, he would need to know the surface area of the tank, to decide on the quantity of tiles required.

Edge of the cubical tank (a) = 1.5 m = 150 cm

So, surface area of the tank $=5 * 150 * 150 \mathrm{~cm}^{2}$

Area of each square tile $=\frac{\text { Surface Area of Tank }}{\text { Area of each Tile }}$

$=\frac{5 \times 150 \times 150}{25 \times 25}$

= 180

Cost of 1 dozen tiles, i.e., cost of 12 tiles = Rs 360

Therefore, cost of one tile = Rs. 360/12 = Rs.30

So, the cost of 180 tiles = 180∗30 = Rs.5400