diff --git a/solutions/object_oriented_design/call_center/call_center.ipynb b/solutions/object_oriented_design/call_center/call_center.ipynb
index 7cef6a2a..c540c6a6 100644
--- a/solutions/object_oriented_design/call_center/call_center.ipynb
+++ b/solutions/object_oriented_design/call_center/call_center.ipynb
@@ -24,9 +24,9 @@
     "    * Operator, supervisor, director\n",
     "* Can we assume operators always get the initial calls?\n",
     "    * Yes\n",
-    "* If there is no free operators or the operator can't handle the call, does the call go to the supervisors?\n",
+    "* If there is no available operators or the operator can't handle the call, does the call go to the supervisors?\n",
     "    * Yes\n",
-    "* If there is no free supervisors or the supervisor can't handle the call, does the call go to the directors?\n",
+    "* If there is no available supervisors or the supervisor can't handle the call, does the call go to the directors?\n",
     "    * Yes\n",
     "* Can we assume the directors can handle all calls?\n",
     "    * Yes\n",