diff --git a/.obsidian/workspace.json b/.obsidian/workspace.json
index 51dce30..ef8cf70 100644
--- a/.obsidian/workspace.json
+++ b/.obsidian/workspace.json
@@ -3,6 +3,24 @@
     "id": "6771390cbd136862",
     "type": "split",
     "children": [
+      {
+        "id": "dcf6a812f6fe360b",
+        "type": "tabs",
+        "children": [
+          {
+            "id": "26ca4bd66426e29b",
+            "type": "leaf",
+            "state": {
+              "type": "markdown",
+              "state": {
+                "file": "Algo/Séminaire/Chapter 3 - Case analysis.md",
+                "mode": "source",
+                "source": false
+              }
+            }
+          }
+        ]
+      },
       {
         "id": "f0451c5f7b886938",
         "type": "tabs",
@@ -69,7 +87,8 @@
       }
     ],
     "direction": "horizontal",
-    "width": 300
+    "width": 300,
+    "collapsed": true
   },
   "right": {
     "id": "b83c16dd7908c658",
@@ -149,10 +168,10 @@
   "active": "bdba25946b821d06",
   "lastOpenFiles": [
     "Algo/Séminaire/Chapter 3 - Case analysis.md",
+    "Algo/Séminaire/Exercices seminaire.md",
     "Algo/Séminaire/Chapter 2 - Functions.md",
     "Algo/Séminaire/Chapter 1 - CAML basics.md",
     "Algo/Séminaire/Introduction.md",
-    "Algo/Séminaire/Exercices seminaire.md",
     "Algo/Séminaire/assets/69E2987C-209A-48CD-8964-5A60462966E5.jpg",
     "Algo/Séminaire/assets",
     "Algo/Séminaire/assets/F1D2AA19-E790-4022-AFFF-F778EAB28AB5.jpg",
diff --git a/Algo/Séminaire/Exercices seminaire.md b/Algo/Séminaire/Exercices seminaire.md
index 23615a4..1efffae 100644
--- a/Algo/Séminaire/Exercices seminaire.md	
+++ b/Algo/Séminaire/Exercices seminaire.md	
@@ -170,4 +170,31 @@ val highest_square_sum : int -> int -> int -> int = <fun>
 
 ```
 
-## Exercise 3.6
+## Exercise 3.7
+```Ocaml
+# let rate_eco kg = match kg with
+	x when x <= 500. -> 3.40
+	| x when x <=1000. -> 4.60
+	| x when x <= 2000. -> 5.10
+	| x when x <= 3000. -> 6.90 ;;
+val rate_eco : float -> float = <fun>
+
+# let rate_standard kg = match kg with
+	x when x <= 500. -> 4.60
+	| x when x <=1000. -> 5.90
+	| x when x <= 2000. -> 6.50
+	| x when x <= 3000. -> 7.20;;
+val rate_standart : float -> float = <fun>
+
+# let rate_express kg = match kg with
+	x when x <= 500. -> 9.10
+	| x when x <=1000. -> 11.
+	| x when x <= 2000. -> 13.5
+	| x when x <= 3000. -> 14.2;;
+val rate_express : float -> float = <fun>
+
+# let rate rt kg = match rt with
+	x when x = "economic" -> rate_eco(kg)
+	| x when x = "standard" -> rate_standard(kg)
+	| x when x = "express" -> rate_express(kg);;
+val rate : string -> float -> float = <fun>