Question

Find the number of coins 1.5 CM in diameter and 2 mm thick to be melted to form a right circular cylinder of radius 2.25 cm and height 10 cm.

Answer 1

Let n o. of coins=x
volume of cylinder=n × π×1.5×1.5×2/10
π×2.25×2.25×10=n×π×2.25/5
22.5=n/5
n=112.5
or
$112 \times \frac{1}{2}$
coins shall be required