# A silver cuboid of dimensions 5.5 cms × 5 cm × 4.2 cms is melted to form circular coins

A silver cuboid of dimensions 5 cms × 5 cm × 4.2 cms is melted to form circular coins of diameter 1.75 cms and thickness 4 mm. Then the number of coins made from the silver metal is (Take π = 22/7)

- 120
- 80
- 60
- 12

**Answer: (1) 120 **

**Solution:-**

The dimensions of a silver cuboid = 5.5 cm, 5 cm & 4.2 cm

Then, the volume of the silver cuboid = 5.5 x 5 x 4.2

= 115.5 cm cube

The diameter of a silver coin = 1.75

Then, the diameter of silver coin = 1.75/2

= 0.875

And the thickness of silver coin = 4 mm

So, the volume of a silver coin = 22 x (0.875)^2 x 0.4/7

= 22 x 0.765625 x 0.4/7

= 0.9625 cm cube

Thus, the number of silver coin in a silver cuboid = 115.5/0.9625

= 120

Hence, the correct answer is option (1) 120.