diff --git a/linked_lists/add_reverse/add_reverse_challenge.ipynb b/linked_lists/add_reverse/add_reverse_challenge.ipynb
index 7e9c74c..6e6b86c 100644
--- a/linked_lists/add_reverse/add_reverse_challenge.ipynb
+++ b/linked_lists/add_reverse/add_reverse_challenge.ipynb
@@ -34,6 +34,8 @@
    "source": [
     "## Constraints\n",
     "\n",
+    "* Can we assume this is a non-circular, singly linked list?\n",
+    "    * Yes\n",
     "* Do we expect the return to be in reverse order too?\n",
     "    * Yes\n",
     "* What if one of the inputs is None?\n",
@@ -41,6 +43,8 @@
     "* How large are these numbers--can they fit in memory?\n",
     "    * Yes\n",
     "* Can we assume we already have a linked list class that can be used for this problem?\n",
+    "    * Yes\n",
+    "* Can we assume this fits in memory?\n",
     "    * Yes"
    ]
   },
diff --git a/linked_lists/add_reverse/add_reverse_solution.ipynb b/linked_lists/add_reverse/add_reverse_solution.ipynb
index e6a3502..7509871 100644
--- a/linked_lists/add_reverse/add_reverse_solution.ipynb
+++ b/linked_lists/add_reverse/add_reverse_solution.ipynb
@@ -33,6 +33,8 @@
    "source": [
     "## Constraints\n",
     "\n",
+    "* Can we assume this is a non-circular, singly linked list?\n",
+    "    * Yes\n",
     "* Do we expect the return to be in reverse order too?\n",
     "    * Yes\n",
     "* What if one of the inputs is None?\n",
@@ -40,6 +42,8 @@
     "* How large are these numbers--can they fit in memory?\n",
     "    * Yes\n",
     "* Can we assume we already have a linked list class that can be used for this problem?\n",
+    "    * Yes\n",
+    "* Can we assume this fits in memory?\n",
     "    * Yes"
    ]
   },
diff --git a/linked_lists/delete_mid/delete_mid_challenge.ipynb b/linked_lists/delete_mid/delete_mid_challenge.ipynb
index 6034abe..1595a0d 100644
--- a/linked_lists/delete_mid/delete_mid_challenge.ipynb
+++ b/linked_lists/delete_mid/delete_mid_challenge.ipynb
@@ -34,6 +34,8 @@
    "source": [
     "## Constraints\n",
     "\n",
+    "* Can we assume this is a non-circular, singly linked list?\n",
+    "    * Yes\n",
     "* What if the final node is being deleted, for example a single node list?  Do we make it a dummy with value None?\n",
     "    * Yes\n",
     "* Can we assume we already have a linked list class that can be used for this problem?\n",
diff --git a/linked_lists/delete_mid/delete_mid_solution.ipynb b/linked_lists/delete_mid/delete_mid_solution.ipynb
index 38b5364..73f6008 100644
--- a/linked_lists/delete_mid/delete_mid_solution.ipynb
+++ b/linked_lists/delete_mid/delete_mid_solution.ipynb
@@ -33,6 +33,8 @@
    "source": [
     "## Constraints\n",
     "\n",
+    "* Can we assume this is a non-circular, singly linked list?\n",
+    "    * Yes\n",
     "* What if the final node is being deleted, for example a single node list?  Do we make it a dummy with value None?\n",
     "    * Yes\n",
     "* Can we assume we already have a linked list class that can be used for this problem?\n",
diff --git a/linked_lists/kth_to_last_elem/kth_to_last_elem_challenge.ipynb b/linked_lists/kth_to_last_elem/kth_to_last_elem_challenge.ipynb
index 071a87c..0ea7ab3 100644
--- a/linked_lists/kth_to_last_elem/kth_to_last_elem_challenge.ipynb
+++ b/linked_lists/kth_to_last_elem/kth_to_last_elem_challenge.ipynb
@@ -34,6 +34,8 @@
    "source": [
     "## Constraints\n",
     "\n",
+    "* Can we assume this is a non-circular, singly linked list?\n",
+    "    * Yes\n",
     "* Can we assume k is a valid integer?\n",
     "    * Yes\n",
     "* If k = 0, does this return the last element?\n",
diff --git a/linked_lists/kth_to_last_elem/kth_to_last_elem_solution.ipynb b/linked_lists/kth_to_last_elem/kth_to_last_elem_solution.ipynb
index e5a2774..cdf23f3 100644
--- a/linked_lists/kth_to_last_elem/kth_to_last_elem_solution.ipynb
+++ b/linked_lists/kth_to_last_elem/kth_to_last_elem_solution.ipynb
@@ -33,6 +33,8 @@
    "source": [
     "## Constraints\n",
     "\n",
+    "* Can we assume this is a non-circular, singly linked list?\n",
+    "    * Yes\n",
     "* Can we assume k is a valid integer?\n",
     "    * Yes\n",
     "* If k = 0, does this return the last element?\n",
diff --git a/linked_lists/linked_list/linked_list_challenge.ipynb b/linked_lists/linked_list/linked_list_challenge.ipynb
index 09ef41b..ac5cf71 100644
--- a/linked_lists/linked_list/linked_list_challenge.ipynb
+++ b/linked_lists/linked_list/linked_list_challenge.ipynb
@@ -34,10 +34,8 @@
    "source": [
     "## Constraints\n",
     "\n",
-    "* Is this a singly or doubly linked list?\n",
-    "    * Singly\n",
-    "* Is this a circular list?\n",
-    "    * No\n",
+    "* Can we assume this is a non-circular, singly linked list?\n",
+    "    * Yes\n",
     "* Do we keep track of the tail or just the head?\n",
     "    * Just the head\n",
     "* Can we insert None values?\n",
diff --git a/linked_lists/linked_list/linked_list_solution.ipynb b/linked_lists/linked_list/linked_list_solution.ipynb
index cc177da..3ba9709 100644
--- a/linked_lists/linked_list/linked_list_solution.ipynb
+++ b/linked_lists/linked_list/linked_list_solution.ipynb
@@ -33,10 +33,8 @@
    "source": [
     "## Constraints\n",
     "\n",
-    "* Is this a singly or doubly linked list?\n",
-    "    * Singly\n",
-    "* Is this a circular list?\n",
-    "    * No\n",
+    "* Can we assume this is a non-circular, singly linked list?\n",
+    "    * Yes\n",
     "* Do we keep track of the tail or just the head?\n",
     "    * Just the head\n",
     "* Can we insert None values?\n",
diff --git a/linked_lists/partition/partition_challenge.ipynb b/linked_lists/partition/partition_challenge.ipynb
index 336d211..1b4cab2 100644
--- a/linked_lists/partition/partition_challenge.ipynb
+++ b/linked_lists/partition/partition_challenge.ipynb
@@ -34,6 +34,8 @@
    "source": [
     "## Constraints\n",
     "\n",
+    "* Can we assume this is a non-circular, singly linked list?\n",
+    "    * Yes\n",
     "* Do we expect the function to return a new list?\n",
     "    * Yes\n",
     "* Can we assume the input x is valid?\n",
diff --git a/linked_lists/partition/partition_solution.ipynb b/linked_lists/partition/partition_solution.ipynb
index 399c0a6..dc4d64b 100644
--- a/linked_lists/partition/partition_solution.ipynb
+++ b/linked_lists/partition/partition_solution.ipynb
@@ -33,6 +33,8 @@
    "source": [
     "## Constraints\n",
     "\n",
+    "* Can we assume this is a non-circular, singly linked list?\n",
+    "    * Yes\n",
     "* Do we expect the function to return a new list?\n",
     "    * Yes\n",
     "* Can we assume the input x is valid?\n",
diff --git a/linked_lists/remove_duplicates/remove_duplicates_challenge.ipynb b/linked_lists/remove_duplicates/remove_duplicates_challenge.ipynb
index 92a728f..2a29b2d 100644
--- a/linked_lists/remove_duplicates/remove_duplicates_challenge.ipynb
+++ b/linked_lists/remove_duplicates/remove_duplicates_challenge.ipynb
@@ -34,8 +34,8 @@
    "source": [
     "## Constraints\n",
     "\n",
-    "* Is this a singly or doubly linked list?\n",
-    "    * Singly\n",
+    "* Can we assume this is a non-circular, singly linked list?\n",
+    "    * Yes\n",
     "* Can you insert None values in the list?\n",
     "    * No\n",
     "* Can we assume we already have a linked list class that can be used for this problem?\n",
diff --git a/linked_lists/remove_duplicates/remove_duplicates_solution.ipynb b/linked_lists/remove_duplicates/remove_duplicates_solution.ipynb
index ef1b974..65c0bd9 100644
--- a/linked_lists/remove_duplicates/remove_duplicates_solution.ipynb
+++ b/linked_lists/remove_duplicates/remove_duplicates_solution.ipynb
@@ -34,8 +34,8 @@
    "source": [
     "## Constraints\n",
     "\n",
-    "* Is this a singly or doubly linked list?\n",
-    "    * Singly\n",
+    "* Can we assume this is a non-circular, singly linked list?\n",
+    "    * Yes\n",
     "* Can you insert None values in the list?\n",
     "    * No\n",
     "* Can we assume we already have a linked list class that can be used for this problem?\n",