Solution

exercise.main/Core.cs

@@ -16,17 +16,31 @@ public class Core
         public bool winningPair(IEnumerable<Tuple<string, string>> hand, out Tuple<string, string> result)
         {
             result = new Tuple<string,string>(string.Empty, string.Empty);
-
 
-
+            int winningHand = 0;
 
-
-
-            return result.Item1!=string.Empty ? true : false;
+            foreach (var pair in hand)
+            {
+                if (pair.Item1 == pair.Item2 && GetValueOfCard(pair.Item1) > winningHand)
+                {
+                    winningHand = GetValueOfCard(pair.Item1);
+                    result = pair;
+                }
+            }
+            return winningHand > 0;
         }
         public int GetValueOfCard(string card)
         {
-            return  0;           
+            if(Int32.TryParse(card, out int result)) return result;
+
+            switch (card.ToUpper())
+            {
+                case "J": { return 11; break; }
+                case "Q": { return 12; break; }
+                case "K": { return 13; break; }
+                case "A": { return 14; break; }
+                default: return 0;
+            }
         }
     }
 }

exercise.main/Extension.cs

@@ -13,7 +13,31 @@ public bool winningThree(IEnumerable<Tuple<string, string, string>> hand, out Tu
         {
             result = new Tuple<string, string, string>(string.Empty, string.Empty, string.Empty);
 
-            return false;
+            int winningHand = 0;
+
+            foreach (var triplet in hand)
+            {
+                if (triplet.Item1 == triplet.Item2 && triplet.Item1 == triplet.Item3 && GetValueOfCard(triplet.Item1) > winningHand)
+                {
+                    winningHand = GetValueOfCard(triplet.Item1);
+                    result = triplet;
+                }
+            }
+            return winningHand > 0;
+        }
+
+        public int GetValueOfCard(string card)
+        {
+            if (Int32.TryParse(card, out int result)) return result;
+
+            switch (card.ToUpper())
+            {
+                case "J": { return 11; break; }
+                case "Q": { return 12; break; }
+                case "K": { return 13; break; }
+                case "A": { return 14; break; }
+                default: return 0;
+            }
         }
 
     }

exercise.tests/ExtensionTests.cs

@@ -0,0 +1,75 @@
+using exercise.main;
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using System.Text;
+using System.Threading.Tasks;
+
+namespace exercise.tests
+{
+    [TestFixture]
+    public class ExtensionTests
+    {
+        [Test]
+        public void Scenario1()
+        {
+            Extension ext = new Extension();
+
+            List<Tuple<string, string, string>> hand = new List<Tuple<string, string, string>>
+        {
+            new Tuple<string, string, string>("K", "5", "K"),
+            new Tuple<string, string, string>("3","7", "3")
+        };
+            Tuple<string, string, string> winner;
+
+            bool result = ext.winningThree(hand, out winner);
+
+            Assert.That(result, Is.False);
+            Assert.That(winner.Item1, Is.EqualTo(String.Empty));
+            Assert.That(winner.Item2, Is.EqualTo(String.Empty));
+            Assert.That(winner.Item2, Is.EqualTo(String.Empty));
+        }
+
+        [Test]
+        public void Scenario2()
+        {
+            Extension ext = new Extension();
+
+            List<Tuple<string, string, string>> hand = new List<Tuple<string, string, string>>
+        {
+            new Tuple<string, string, string>("5", "5", "K"),
+            new Tuple<string, string, string>("J","J", "J")
+        };
+            Tuple<string, string, string> winner;
+
+            bool result = ext.winningThree(hand, out winner);
+
+            Assert.That(result, Is.True);
+            Assert.That(winner.Item1, Is.EqualTo("J"));
+            Assert.That(winner.Item1, Is.EqualTo("J"));
+            Assert.That(winner.Item1, Is.EqualTo("J"));
+
+        }
+
+        [Test]
+        public void Scenario3()
+        {
+            Extension ext = new Extension();
+
+            List<Tuple<string, string, string>> hand = new List<Tuple<string, string, string>>
+        {
+            new Tuple<string, string, string>("7", "7", "7"),
+            new Tuple<string, string, string>("A","A", "A")
+        };
+            Tuple<string, string, string> winner;
+
+            bool result = ext.winningThree(hand, out winner);
+
+            Assert.That(result, Is.True);
+            Assert.That(winner.Item1, Is.EqualTo("A"));
+            Assert.That(winner.Item1, Is.EqualTo("A"));
+            Assert.That(winner.Item1, Is.EqualTo("A"));
+
+        }
+    }
+}