Diameter of solid metallic sphere = 6 cm
So, its radius = 3 cm
Height of solid metal cone = 45
Diameter of metal cone = 12 cm
Its radius = 6 cm
Let the number of solid metallic spheres be ‘n’
\[\begin{array}{*{35}{l}}
Volume\text{ }of\text{ }1\text{ }sphere\text{ }=\text{ }4/3\text{ }\pi \text{ }{{\left( 3 \right)}^{3}} \\
Volume\text{ }of\text{ }metallic\text{ }cone\text{ }=\text{ }1/3\text{ }\pi {{6}^{2}}~x\text{ }45 \\
\end{array}\]
Hence, n = Volume of metal cone/ Volume of 1 sphere
\[\begin{array}{*{35}{l}}
n\text{ }=\text{ }\left( 1/3\text{ }\pi {{6}^{2}}~x\text{ }45 \right)/\text{ }\left( 4/3\text{ }\pi \text{ }{{\left( 3 \right)}^{3}} \right) \\
=\text{ }\left( 6\text{ x }6\text{ x }45 \right)/\text{ }\left( 4\text{ x }3\text{ x }3\text{ x }3 \right) \\
n\text{ }=\text{ }15 \\
\end{array}\]