Question

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

• A. Rs. 5600
• B. Rs. 6400
• C. Rs. 5400
• D. Rs. 4500

Answer 1

The correct option is C Rs. 5400

The length of the each side of water tank = 1.5 m = 150 cm
As it is given that base is not covered with tiles so, five sides of the tank at covered with tiles.
Therefore,
Surface area of water tank $=5a^2=5(150{)}^2=112500{\text{cm}}^2$
Side of tile = 25 cm
Area of tile $={25}^2=625{\text{cm}}^2$
Number of tiles to cover five sides of the tank $=\frac{112500}{625}=180$
Now,
Cost of one dozen tiles = Rs. 360
Hence, total cost of $180=\frac{360}{12}\times 80=Rs.5400$