If \(y\) varies jointly with \(x\) and \(z\) , and \(y = 60\) when \(x = 3\) and \(z = 4\) , find \(y\) when \(x = 6\) and \(z = 8\) .

If \(y\) varies directly with \(x\) and inversely with \(z\) , and \(y = 12\) when \(x = 4\) and \(z = 2\) , find \(y\) when \(x = 6\) and \(z = 3\) .

\[y = 12\]

\[V = 60\]

\[V = kTP\]

\[k = 6\]