diff --git a/source/sec-Covariance.ptx b/source/sec-Covariance.ptx
index 2b0983b..2843a09 100644
--- a/source/sec-Covariance.ptx
+++ b/source/sec-Covariance.ptx
@@ -214,6 +214,12 @@
           </tabular>
         </table>
       </statement>
+
+      <answer>
+        <p>
+          <m>0.048</m>.
+        </p>
+      </answer>
     </exercise>
 
     <exercise>
@@ -228,6 +234,12 @@
           [Note: Somewhat tedious.]
         </p>
       </statement>
+
+      <answer>
+        <p>
+          <m>\frac{25}{4}</m>.
+        </p>
+      </answer>
     </exercise>
     </exercises>
   </section>
\ No newline at end of file