What is the number of gold coins, each having a radius of…

What is the number of gold coins, each having a radius of 0.875 cm and a thickness of 2 mm, that need to be melted to create a cuboid with dimensions 5.5 cm × 5 cm × 3.5 cm? (Use π = $22\over7$ )

Show answer & explanation

Correct answer: D

Explanation

The correct answer is Option 4 i.e. 200.

Radius of coin = 0.875 cm

Thickness (height) of coin = 2 mm = 0.2 cm

Volume of one coin = πr²h

⇒ ${22\over7}\times(0.875)^2\times0.2$ = 0.48125

Volume of cuboid = 5.5 × 5 × 3.5 = 96.25 cm³

Number of coins = $96.25\over0.48125$ = 200

SSC MTS 2024 PYQ — Question 7