Done

app/application.rb

@@ -0,0 +1,24 @@
+class Application
+
+  @@items = []
+  @@items << Item.new("Pear", 3.42)
+
+  def call(env)
+    resp = Rack::Response.new
+    req = Rack::Request.new(env)
+
+    if req.path.match(/items/)
+     item_name = req.path.split("/items/").last
+       if item = @@items.find{|i| i.name == item_name}
+        resp.write item.price
+      else
+        resp.status = 400
+        resp.write "Item not found"
+      end
+  else
+      resp.status = 404
+      resp.write "Route not found"
+    end
+    resp.finish
+  end
+end