Question

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?

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Answer 1

Answer:

400

Step-by-step explanation:

Find the radius:

Radius = Diameter ÷ 2

Radius = 1.75 ÷ 2 = 0.875

Convert 2mm to cm

2mm = 0.2 cm

Find the volume of 1 coin:

Volume = πr²h

Volume = π (0.875)² (0.2)

volume = 0.481 cm³

Find the volume of the cuboid:

Volume = Length x Breadth x Height

Volume = 5.5 x 10 x 3.5 = 192.5 cm³

Find the number of coins needed;

Number of coins = 192.5 ÷ 0.481

Number of coins = 400

Answer: 401 coins.

Answer 2

Please refer to the attachment.