** **Rachel, an engineering student, was asked to make a model shaped like a cylinder with two cones attached at its two ends by using a thin aluminium sheet. The diameter of the model is 3 cm and its length is 12 cm. If each cone has a height of 2 cm, find the volume of air contained in the model that Rachel made. (Assume the outer and inner dimensions of the model to be nearly the same.)

**Solution:**

Diameter of Cylinder = Diameter of Cones = 3 cm

## Radius of Cylinder = Radius of Cones **cm**

Height of each cone 2** cm**

Length of model = 12 cm

**Height of Cylinder = h = Total Height of Model - Height of Ist Cone - Height of Second Cone**

**cm**

**Volume of air in the model = Volume of Solid = Volume of Cylinder + Volume of 1st Cone + Volume of 2nd Cone**