diff --git a/README.md b/README.md
index 2e048600..fde1824b 100644
--- a/README.md
+++ b/README.md
@@ -438,3 +438,4 @@ Profile on LeetCode: [fartem](https://leetcode.com/fartem/).
 | 2455. Average Value of Even Numbers That Are Divisible by Three    | [Link](https://leetcode.com/problems/average-value-of-even-numbers-that-are-divisible-by-three/)    | [Link](./lib/easy/2455_average_value_of_even_numbers_that_are_divisible_by_three.rb)    |
 | 2460. Apply Operations to an Array                                 | [Link](https://leetcode.com/problems/apply-operations-to-an-array/)                                 | [Link](./lib/easy/2460_apply_operations_to_an_array.rb)                                 |
 | 2469. Convert the Temperature                                      | [Link](https://leetcode.com/problems/convert-the-temperature/)                                      | [Link](./lib/easy/2469_convert_the_temperature.rb)                                      |
+| 2475. Number of Unequal Triplets in Array                          | [Link](https://leetcode.com/problems/number-of-unequal-triplets-in-array/)                          | [Link](./lib/easy/2475_number_of_unequal_triplets_in_array.rb)                          |
diff --git a/leetcode-ruby.gemspec b/leetcode-ruby.gemspec
index 81491bd5..7b9103d0 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 = '5.7.7'
+  s.version = '5.7.8'
   s.license = 'MIT'
   s.files = ::Dir['lib/**/*.rb'] + %w[bin/leetcode-ruby README.md LICENSE]
   s.executable = 'leetcode-ruby'
diff --git a/lib/easy/2475_number_of_unequal_triplets_in_array.rb b/lib/easy/2475_number_of_unequal_triplets_in_array.rb
new file mode 100644
index 00000000..b30e03a8
--- /dev/null
+++ b/lib/easy/2475_number_of_unequal_triplets_in_array.rb
@@ -0,0 +1,18 @@
+# frozen_string_literal: true
+
+# https://leetcode.com/problems/number-of-unequal-triplets-in-array/
+# @param {Integer[]} nums
+# @return {Integer}
+def unequal_triplets(nums)
+  result = 0
+  n = nums.length
+  (0...n).each do |i|
+    ((i + 1)...n).each do |j|
+      ((j + 1)...n).each do |k|
+        result += 1 if nums[i] != nums[j] && nums[j] != nums[k] && nums[i] != nums[k]
+      end
+    end
+  end
+
+  result
+end
diff --git a/test/easy/test_2475_number_of_unequal_triplets_in_array.rb b/test/easy/test_2475_number_of_unequal_triplets_in_array.rb
new file mode 100644
index 00000000..06b6c0a8
--- /dev/null
+++ b/test/easy/test_2475_number_of_unequal_triplets_in_array.rb
@@ -0,0 +1,12 @@
+# frozen_string_literal: true
+
+require_relative '../test_helper'
+require_relative '../../lib/easy/2475_number_of_unequal_triplets_in_array'
+require 'minitest/autorun'
+
+class NumberOfUnequalTripletsInArrayTest < ::Minitest::Test
+  def test_default
+    assert_equal(3, unequal_triplets([4, 4, 2, 4, 3]))
+    assert_equal(0, unequal_triplets([1, 1, 1, 1, 1]))
+  end
+end