Height of cylindrical container=15cm
Radius of cylindrical container=6cm
Volume of container=πr2h=3.14×6×6×15
=1695.6cm3
Quantity of ice cream each child gets =1695.610=169.56cm3
Let radius of cone=r=radius of hemisphere
∴Height of cone=4r
Volume of hemisphere+volume of cone=169.56cm3
⇒23πr3+13πr2h=169.56
⇒23×3.14×r3+13×3.14×r2×4r=169.56
⇒2.09r3+4.18r3=169.56
⇒6.27r3=169.56
⇒6.27r3=169.56
⇒r3=169.566.27≈27
⇒r=3cm
Therefore, radius of the ice cream cone is 3cm