diff --git a/source/calculus/source/04-IN/01.ptx b/source/calculus/source/04-IN/01.ptx
index 040f985ce..662f0146b 100644
--- a/source/calculus/source/04-IN/01.ptx
+++ b/source/calculus/source/04-IN/01.ptx
@@ -30,6 +30,11 @@
                 <li><p>3</p></li>
                 <li><p>4</p></li>
             </ol>
+            <answer>
+                <p>
+                  A  
+                </p>
+            </answer>
     </activity>    
     
 
@@ -42,6 +47,11 @@
                 <li><p>3</p></li>
                 <li><p>4</p></li>
             </ol>
+            <answer>
+                <p>
+                  B  
+                </p>
+            </answer>
     </activity>    
     
 <activity>
@@ -53,6 +63,11 @@
                 <li><p>3</p></li>
                 <li><p>4</p></li>
             </ol>
+            <answer>
+                <p>
+                   C 
+                </p>
+            </answer>
     </activity>  
     
     
@@ -65,6 +80,11 @@
                   <li><p><m>3\pi</m></p></li>
                 <li><p><m>4\pi</m></p></li>
             </ol>
+            <answer>
+                <p>
+                    B
+                </p>
+            </answer>
     </activity>  
  
     <definition>
@@ -89,7 +109,11 @@
         </ol>
         </p>
     </statement>
-       
+       <answer>
+        <li><p><m>-\frac{45}{2}</m></p></li>
+            <li><p><m>-4 \, \pi</m></p></li>
+            <li><p><m>-24</m></p></li>
+       </answer>
        </activity>
 <!--     <answer>
 <p>
@@ -137,9 +161,15 @@
     <task> <p> Find <m>\int_{3}^{6} g(t) \, dt</m></p></task>
         <task> <p> Find <m>\int_{0}^{10} g(t) \, dt</m></p></task>
         <task> <p> Suppose that <m>g(t)</m> gives the velocity in fps at time <m>t</m> (in seconds) of a particle moving in the vertical direction. A positive velocity indicates that the particle is moving up, a negative velocity indicates that the particle is moving down. If the particle started at a height of 3ft, at what height would it been after 3 seconds? After 6 seconds? After 10 seconds? At what time does the particle reach the highest point in this time interval?</p></task>
+  
+    <answer>
+    <p>
+        
+    </p>
+   </answer>
     </activity>
 
-    
+
     </subsection>
     <subsection>
         <title>Videos</title>