The ratio of the radius and slant height of a cone is $3:5$ and its curved surface area is $423.9 \, cm^2$. Find its volume. $(\pi = 3.14)$ (in $cm^3$)

Hameed has built a cubical water tank with a 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 $25\, cm$ (see figure). Find how much he would spend on the tiles,if the cost of the tiles is $Rs. 360$ per dozen.

The areas of the three adjacent faces meeting at one vertex of a cuboid are $4000 \, cm^2$,$2000 \, cm^2$,and $3200 \, cm^2$ respectively. Find the dimensions and the volume of the cuboid.

$A$ cuboidal water tank is $2\, m$ long,$1\, m$ wide,and $80\, cm$ deep (height). Its remaining five surfaces,excluding the base,are covered with square tiles of size $20\, cm \times 20\, cm$. Find the number of tiles required.

The length,breadth,and height of a cuboid are $20\, cm$,$15\, cm$,and $12\, cm$ respectively. Find its total surface area (in $cm^2$).

There are two boxes of metal sheet. The length,width,and height of a cuboidal box are $30 \, cm$,$25 \, cm$,and $20 \, cm$ respectively. $A$ cubical box has each edge of $25 \, cm$. Find out which box requires more metal sheet and by how many $cm^2$?