A pen stand is made up of wood and is in the shape of a cuboid with four conical depressions and cylindrical…

A pen stand is made up of wood and is in the shape of a cuboid with four conical depressions and cylindrical extensions to hold pens. The depressions are hollowed out from the wooden cuboidal stand and cylindrical extensions are made up of metal attached separately as shown in the figure given below : The dimensions of the cuboidal block of wood are $15$ cm $\times$ $10$ cm $\times$ $3.5$ cm. The radius of each conical depression is $0.5$ cm and depth is $1.4$ cm. The radius and height of each cylindrical metal extension are $0.5$ cm and $4.9$ cm respectively.