diff --git a/2022/ruby/day_11.rb b/2022/ruby/day_11.rb
new file mode 100644
index 0000000..2bdfcf9
--- /dev/null
+++ b/2022/ruby/day_11.rb
@@ -0,0 +1,35 @@
+Monkey = Struct.new(:id, :items, :operation, :test, :throw_to)
+
+monkeys = ARGF.read.split("\n\n").map {|raw|
+  raw = raw.lines(chomp: true)
+  id = raw.shift.match(/\d+/)[0].to_i
+  starting_items = raw.shift.match(/: (.+)/)[1].split(", ").map(&:to_i)
+  operation_ = raw.shift.match(/: new = (.+)/)[1]
+  operation = ->(old) { eval(operation_) }
+  test = raw.shift.match(/\d+/)[0].to_i
+  t = raw.shift.match(/\d+/)[0].to_i
+  f = raw.shift.match(/\d+/)[0].to_i
+  throw_to = ->(n) { (n % test).zero? ? t : f }
+  Monkey.new(id, starting_items, operation, test, throw_to)
+}
+
+max_worry = monkeys.map(&:test).inject(:*)
+
+inspections = Hash.new(0)
+# 20.times do
+10_000.times do
+  monkeys.each do |monkey|
+    until monkey.items.empty?
+      inspections[monkey.id] += 1
+
+      item = monkey.items.shift
+      item = monkey.operation.(item)
+      # item /= 3
+      item %= max_worry
+      to = monkey.throw_to.(item)
+      monkeys[to].items << item
+    end
+  end
+end
+
+p inspections.values.max(2).inject(:*)