Find the surface area of a sphere with a diameter of $3.5 \, cm$. Assume $\pi = \frac{22}{7}$. (in $, cm^2$)

$A$ cuboidal water tank is $6 \,m$ long,$5 \,m$ wide and $4.5 \,m$ deep. How many litres of water can it hold (in $,l$)? $(1 \,m^3 = 1000 \,l)$

$A$ bus stop is barricaded from the remaining part of the road by using $50$ hollow cones made of recycled cardboard. Each cone has a base diameter of $40 \, cm$ and height $1 \, m$. If the outer side of each of the cones is to be painted and the cost of painting is $Rs. 12$ per $m^2$,what will be the cost of painting all these cones? (Use $\pi = 3.14$ and take $\sqrt{1.04} = 1.02$)

In the figure,you see the frame of a lampshade. It is to be covered with a decorative cloth. The frame has a base diameter of $20 \, cm$ and a height of $30 \, cm$. $A$ margin of $2.5 \, cm$ is to be given for folding it over the top and bottom of the frame. Find how much cloth is required for covering the lampshade. $\left[ \text{Assume } \pi = \frac{22}{7} \right]$ (in $, cm^2$)

$A$ river $3 \,m$ deep and $40 \,m$ wide is flowing at the rate of $2 \,km$ per hour. How much water will fall into the sea in a minute (in $,m^3$)?

$A$ wooden bookshelf has external dimensions as follows: Height $= 110\, cm$,Depth $= 25\, cm$,Breadth $= 85\, cm$ (see Fig.). The thickness of the plank is $5\, cm$ everywhere. The external faces are to be polished and the inner faces are to be painted. If the rate of polishing is $20$ paise per $cm^2$ and the rate of painting is $10$ paise per $cm^2$,find the total expenses required for polishing and painting the surface of the bookshelf.