$A$ pen stand made of wood is in the shape of a cuboid with four conical depressions to hold pens. The dimensions of the cuboid are $15 \, cm$ by $10 \, cm$ by $3.5 \, cm$. The radius of each of the depressions is $0.5 \, cm$ and the depth is $1.4 \, cm$. Find the volume of wood in the entire stand (in $cm^3$). [Take $\pi = \frac{22}{7}$]

$A$ solid iron pole consists of a cylinder of height $220 \,cm$ and base diameter $24 \,cm$,which is surmounted by another cylinder of height $60 \,cm$ and radius $8 \,cm$. Find the mass of the pole,given that $1 \,cm^3$ of iron has approximately $8 \,g$ mass. (in $kg$) (Use $\pi = 3.14$)

$A$ hemispherical tank full of water is emptied by a pipe at the rate of $3 \frac{4}{7}$ $litres$ per $second.$ How much time will it take to empty half the tank,if it is $3 \,m$ in $diameter?$ (in $minutes$) (Take $\pi=\frac{22}{7}$)

$A$ container,opened from the top and made up of a metal sheet,is in the form of a frustum of a cone of height $16 \, cm$ with radii of its lower and upper ends as $8 \, cm$ and $20 \, cm$,respectively. Find the cost of the milk which can completely fill the container,at the rate of $Rs. \, 20$ per litre. Also,find the cost of the metal sheet used to make the container,if it costs $Rs. \, 8$ per $100 \, cm^2$. (Take $\pi = 3.14$)

An oil funnel made of a tin sheet consists of a $10 \, cm$ long cylindrical portion attached to a frustum of a cone. If the total height is $22 \, cm$,the diameter of the cylindrical portion is $8 \, cm$,and the diameter of the top of the funnel is $18 \, cm$,find the area of the tin sheet required to make the funnel.

$A$ $20\, m$ deep well with diameter $7\, m$ is dug and the earth from digging is evenly spread out to form a platform $22\, m$ by $14\, m$. Find the height of the platform. (in $m$) [Take $\pi=\frac{22}{7}$]