-
The number of coins of radius 0.75 cm and thickness 0.2cm required to be melted to make a right circular cylinder of height 8 cm and base radius 3 cm is :
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- 500
- 600
- 460
- 640
- 500
Correct Option: D
Volume of 1 coin = πr²h
= (π × 0.75 × 0.75 × 0.2) cu. cm.
Volume of cylinder = (π × 3 × 3 × 8) cu. cm.
| ∴ Number of coins = | ||
| π × 0.75 × 0.75 × 0.2 |
| = | ||
| 75 × 75 × 2 |
= 640
