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

Question

Philoid · Accepted Answer

Given, that dimensions of cuboid formed is 5.5 × 10 × 3.5 and the diameter(d) of cylindrical coin is 1.75 cm and height(h) is 2mm = 0.2cm.

⇒ l = 5.5, b = 10 and h = 3.5

⇒ radius(r) of coin (∵ )

⇒ vol. of silver coin = πr²h

= 3.14 × 0.878 × 0.875 × 0.2

= 0.48

⇒ vol. of cuboid = lbh

= 5.5 × 10 × 3.5

= 192.5

⇒ ∴ no. of silver coins

= 400