Question

6. 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 x 10 cm x 3.5 cm?



​

Answer 1

Answer:

400

Step-by-step explanation:

(i) Dimensions of coin:

Diameter = 1.75 cm.

Radius = 0.875 cm.

Thickness = h = 2 mm = 0.2 cm.

Volume of coin = πr²h

                          = (22/7) * (0.875)² * 0.2

                          = 0.48125 cm³

(ii) Dimensions of cuboid:

Length = 5.5 cm.

Breadth = 10 cm.

Height = 3.5 cm.

Volume of cuboid = Length * Breadth * Height

                              = 5.5 * 10 * 3.5

                              = 192.5 cm³

∴ Number of coins = (Volume of cuboid)/(Volume of coin)

                               = 192.5/0.48125

                               = 400.

∴ Total number of coins = 400.

Hope it helps!