How many silver coins, 1.75 cm in diameter and of thickness 2 mm, must be melted to form a cuboid of dimensions 5.5 cm × 10 cm × 3.5 cm?

**Solution:**

**Let number of silver coins be n**

Volume of cuboid = length x breadth x height

**Silver coin is a cylinder. Thickness of silver coin is height of cylinder.**

Height of coin (cylinder) = h =2 mm=0.2 cm

Diameter of coin (cylinder) **cm**

Radius of silver coin (cylinder) **cm**

Volume of silver coin (cylinder)

**According to given condition we have**

**Volume of coin = Volume of cuboid**