diff --git a/optimization/exercises/singVarCalcOptimization9.tex b/optimization/exercises/singVarCalcOptimization9.tex
index c4026db7d..4d0f1a1f1 100644
--- a/optimization/exercises/singVarCalcOptimization9.tex
+++ b/optimization/exercises/singVarCalcOptimization9.tex
@@ -10,7 +10,7 @@
 \begin{document}
 \begin{exercise}
 
-  You want to make cylindrical containers to hold 1 liter (1000$\text{cm}^3$) using the
+  You want to make a cylindrical container to hold 1 liter (1000$\text{cm}^3$) using the
   least amount of construction material.  The side is made from a
   rectangular piece of material, and this can be done with no material
   wasted.  However, the top and bottom are cut from squares of side
@@ -52,7 +52,7 @@
   \end{image}
   \end{hint}
   \begin{hint}
-  Use the fact that the volume of the cylinder, $V=r^2\cdot\pi\cdot h$ and that $V=1000$.
+  Use the facts that the volume of the cylinder is $V=r^2\cdot\pi\cdot h$ and that $V=1000$.
   Express $h$ in terms of $r$.
   Now you can express $S$ as a function of $r$.
     \end{hint}