diff --git a/README.md b/README.md
index d741b4cf..8942be93 100644
--- a/README.md
+++ b/README.md
@@ -736,6 +736,7 @@ Profile on LeetCode: [fartem](https://leetcode.com/fartem/).
 | 2109. Adding Spaces to a String                                                     | [Link](https://leetcode.com/problems/adding-spaces-to-a-string/)                                                     | [Link](./lib/medium/2109_adding_spaces_to_a_string.rb)                                                     | [Link](./test/medium/test_2109_adding_spaces_to_a_string.rb)                                                     |
 | 2116. Check if a Parentheses String Can Be Valid                                    | [Link](https://leetcode.com/problems/check-if-a-parentheses-string-can-be-valid/)                                    | [Link](./lib/medium/2116_check_if_a_parentheses_string_can_be_valid.rb)                                    | [Link](./test/medium/test_2116_check_if_a_parentheses_string_can_be_valid.rb)                                    |
 | 2121. Intervals Between Identical Elements                                          | [Link](https://leetcode.com/problems/intervals-between-identical-elements/)                                          | [Link](./lib/medium/2121_intervals_between_identical_elements.rb)                                          | [Link](./test/medium/test_2121_intervals_between_identical_elements.rb)                                          |
+| 2125. Number of Laser Beams in a Bank                                               | [Link](https://leetcode.com/problems/number-of-laser-beams-in-a-bank/)                                               | [Link](./lib/medium/2125_number_of_laser_beams_in_a_bank.rb)                                               | [Link](./test/medium/test_2125_number_of_laser_beams_in_a_bank.rb)                                               |
 | 2425. Bitwise XOR of All Pairings                                                   | [Link](https://leetcode.com/problems/bitwise-xor-of-all-pairings/)                                                   | [Link](./lib/medium/2425_bitwise_xor_of_all_pairings.rb)                                                   | [Link](./test/medium/test_2425_bitwise_xor_of_all_pairings.rb)                                                   |
 | 2429. Minimize XOR                                                                  | [Link](https://leetcode.com/problems/minimize-xor/)                                                                  | [Link](./lib/medium/2429_minimize_xor.rb)                                                                  | [Link](./test/medium/test_2429_minimize_xor.rb)                                                                  |
 | 2657. Find the Prefix Common Array of Two Arrays                                    | [Link](https://leetcode.com/problems/find-the-prefix-common-array-of-two-arrays/)                                    | [Link](./lib/medium/2657_find_the_prefix_common_array_of_two_arrays.rb)                                    | [Link](./test/medium/test_2657_find_the_prefix_common_array_of_two_arrays.rb)                                    |
diff --git a/leetcode-ruby.gemspec b/leetcode-ruby.gemspec
index 16699ef5..ff26e106 100644
--- a/leetcode-ruby.gemspec
+++ b/leetcode-ruby.gemspec
@@ -5,7 +5,7 @@ require 'English'
 ::Gem::Specification.new do |s|
   s.required_ruby_version = '>= 3.0'
   s.name = 'leetcode-ruby'
-  s.version = '9.0.1'
+  s.version = '9.0.2'
   s.license = 'MIT'
   s.files = ::Dir['lib/**/*.rb'] + %w[README.md]
   s.executable = 'leetcode-ruby'
diff --git a/lib/medium/2125_number_of_laser_beams_in_a_bank.rb b/lib/medium/2125_number_of_laser_beams_in_a_bank.rb
new file mode 100644
index 00000000..f45c8b66
--- /dev/null
+++ b/lib/medium/2125_number_of_laser_beams_in_a_bank.rb
@@ -0,0 +1,22 @@
+# frozen_string_literal: true
+
+# https://leetcode.com/problems/number-of-laser-beams-in-a-bank/
+# @param {String[]} bank
+# @return {Integer}
+def number_of_beams(bank)
+  lasers = []
+
+  bank.each do |b|
+    lasers_at_b = b.count('1')
+
+    lasers << lasers_at_b if lasers_at_b.positive?
+  end
+
+  result = 0
+
+  (1...lasers.size).each do |i|
+    result += lasers[i - 1] * lasers[i]
+  end
+
+  result
+end
diff --git a/test/medium/test_2125_number_of_laser_beams_in_a_bank.rb b/test/medium/test_2125_number_of_laser_beams_in_a_bank.rb
new file mode 100644
index 00000000..6c78540a
--- /dev/null
+++ b/test/medium/test_2125_number_of_laser_beams_in_a_bank.rb
@@ -0,0 +1,34 @@
+# frozen_string_literal: true
+
+require_relative '../test_helper'
+require_relative '../../lib/medium/2125_number_of_laser_beams_in_a_bank'
+require 'minitest/autorun'
+
+class NumberOfLaserBeamsInABankTest < ::Minitest::Test
+  def test_default_one
+    assert_equal(
+      8,
+      number_of_beams(
+        %w[
+          011001
+          000000
+          010100
+          001000
+        ]
+      )
+    )
+  end
+
+  def test_default_two
+    assert_equal(
+      0,
+      number_of_beams(
+        %w[
+          000
+          111
+          000
+        ]
+      )
+    )
+  end
+end