diff --git a/lib/6.11-replace_loop_with_collection_closure_method.rb b/lib/6.11-replace_loop_with_collection_closure_method.rb
new file mode 100644
index 0000000..aefcfc3
--- /dev/null
+++ b/lib/6.11-replace_loop_with_collection_closure_method.rb
@@ -0,0 +1,49 @@
+class ReplaceLoopWithCollectionClosureMethod
+  class Company
+    attr_reader :employees
+    def initialize(employee_list)
+      @employees = employee_list.map{|row|Employee.new(position: row[:position], office: row[:office], salary: row[:salary])}
+    end
+
+    def select_managers
+      managers = []
+      employees.each do |e|
+        managers << e if e.manager?
+      end
+      return managers
+    end
+
+    def employees_offices
+      offices = []
+      employees.each {|e| offices << e.office}
+      return offices
+    end
+
+    def manager_offices
+      offices = []
+      employees.each do |e|
+        offices << e.office if e.manager?
+      end
+      return offices
+    end
+
+    def total_salary
+      total = 0
+      employees.each{|e| total += e.salary}
+      return total
+    end
+  end
+
+  class Employee
+    attr_accessor :position, :office, :salary
+    def initialize(arg={})
+      self.position = arg[:position]
+      self.office = arg[:office]
+      self.salary = arg[:salary]
+    end
+
+    def manager?
+      position == 255
+    end
+  end
+end
diff --git a/spec/6.11-replace_loop_with_collection_closure_method_spec.rb b/spec/6.11-replace_loop_with_collection_closure_method_spec.rb
new file mode 100644
index 0000000..5606902
--- /dev/null
+++ b/spec/6.11-replace_loop_with_collection_closure_method_spec.rb
@@ -0,0 +1,54 @@
+require 'spec_helper'
+describe ReplaceLoopWithCollectionClosureMethod do
+
+  let(:complany_employees) {
+    ReplaceLoopWithCollectionClosureMethod::Company.new(
+      [
+        {
+          position: 1,
+          office: "大阪",
+          salary: 100
+        },
+        {
+          position: 1,
+          office: "大阪",
+          salary: 1000
+        },
+        {
+          position: 255,
+          office: "東京",
+          salary: 10000
+        }
+      ]
+    )
+
+  }
+
+  describe '#select_managers' do
+    it 'returns only manager employee' do
+      expected = ReplaceLoopWithCollectionClosureMethod::Employee.new(position: 255, office: "東京", salary: 10000)
+      expect(complany_employees.select_managers.count).to eq 1
+      expect(complany_employees.select_managers.first.position).to eq expected.position
+      expect(complany_employees.select_managers.first.office).to eq expected.office
+      expect(complany_employees.select_managers.first.salary).to eq expected.salary
+    end
+  end
+
+  describe '#employees_offices' do
+    it 'returns contain 大坂 and 東京' do
+      expect(complany_employees.employees_offices).to eq(["大阪","大阪","東京"])
+    end
+  end
+
+  describe '#manager_offices' do
+    it 'returns contain 東京' do
+      expect(complany_employees.manager_offices).to eq(["東京"])
+    end
+  end
+
+  describe '#total_salary' do
+    it 'returns is 11100' do
+      expect(complany_employees.total_salary).to eq(11100)
+    end
+  end
+end