[tex]\bf \begin{array}{cccccclllll}
\textit{something}&&\textit{varies directly to}&&\textit{something else}\\ \quad \\
\textit{something}&=&{{ \textit{some value}}}&\cdot &\textit{something else}\\ \quad \\
y&=&{{ k}}&\cdot&x
\\
&& y={{ k }}x
\end{array}[/tex]
"The volume of a pyramid very jointly as its height and the area of its base the pyramid " [tex]\bf V=kBh\qquad
\begin{cases}
k=\textit{constant of variation}\\
B=\textit{area of base}\\
h=height
\end{cases}
\\\\\\
\textit{now, we know that }
\begin{cases}
h=15\\
B=10\\
V=50
\end{cases}\implies 50=k\cdot 10\cdot 15
\\\\\\
50=150k\implies \cfrac{50}{150}=k\implies \cfrac{1}{3}=k
\\\\\\
thus\implies \boxed{V=\cfrac{1}{3}Bh}[/tex]
now, what's the height of a pyramid with V=60 and B=12? [tex]\bf \begin{array}{llll}
60=\cfrac{1}{3}\cdot &10\cdot h\\
\uparrow &\uparrow \\
V&B
\end{array}[/tex]
solve for "h"
