Question

A pen stand is made of wood in the shape of cuboid with three conical depression to hold the Pens.The dimensions of the cuboid are 15cm by 10cm by 3.5cm.The radius of each of the depression is 0.5cm and the depth is 1.4cm. Find the volume of the wood in the entire stand.

Answer 1

Here it is Class 10 chapter 13 surface areas and volumes 

Answer 2

the volume of the wood in entire stand =volume of entire cuboidal pen stand-3×volume of conical depression
=15 × 10 × 3.5 -3 ×1 /3×22/7 ×0.5 × 0.5 ×1.4
=525-22/7×0.25×1.4
=525-22×0.2×0.25
=525-22×0.05
=525-1.1
=523.9