Question

The number of coins of radius 0.75 cm and thickness 0.2 cm to be melted to make a right circular cylinder of height 8 cm and base radius 3 cm is:

• A. 460
• B. 500
• C. 600
• D. 640
• E. 780

Answer 1

The correct option is D

640

Number of coins = $\left(\frac{\pi \times 8\times 3\times 3}{\pi \times 0.75\times 0.75\times 0.2}\right)$ = 640